Neco 2016 GENERAL MATHEMATICS Obj And Theory/ Essay Answers- Expo June/July
NOTICE NOTE
/ means DIVISION
* means Multiplication
tita You Should Know that.
rais means Raise to power or
^ means Raise to power
sqr rut/square rut means Square root
—–(1) means Equation 1
yr means Year
f(x-xbar) means x MINUS x BAR as in statistics
which means that MINUS will be on Top of x.
, (Comma) means NEXT LINE,
This means that The Following Number is Under
The Number
its Following ie.
UNDER. It is usually used during STATISTICS when drawing a table.
1) ,(comma) means next line.
(e.g)
x : 1,2,3
fx : 4,5,6
fx-xbar : 7,8,9
x|fx |x¯¯|
1| 4 | 7 |
NECO (MATHEMATICS) ANSWER
VERIFIED MATHS OBJ
1-10 ecadddceee
11-20 ccdcaaceca
21-30 dcdeeccded
31-40 eaadbeeadc
41-50 bbdccdcecb
51-60 cadaccbdee
Math eassy
8a )
| AD | ^2= 13^2- 5^2
| AD | ^2= 169- 25
| AD | ^2= 144
AD= sqr144
AD= 12CM
| AD | =12 -r
r ^2=( 12- r )^2 - 5^2
r ^2=( 12- r )(12 -r ) +25
r ^2=144 -24 r +25
r ^2=169 -24 r
r ^2+24 r -169 =0
r ^2+24 r =169
r ^2+24 r +14^2= 169+14 ^2
(r +14 )^2= 169+196
(r +14 )^2= 365
(r +14 =sqr 365
r +14= 19. 105
r =19. 105- 14
r =5. 105
r =5. 1cm
.
8aii )
circumfrenece of a circle = 2pie R
C =2x 22 /2*(5. 1)^2
C =1144 . 44/7
C =163. 4914 cm
C =163. 5cm
.
8b)
y 2- y 1/x 2 -x 1 =y - y 1/x - x 1
6- 2/2- (- 1)=y -2/x -( -1)
4/2+1 = y -2 /x +1
4/3=y -2/x +1
3(y -2)= 4( x +1)
3y - 6=4x +4
3y - 4x =4 +6
3y - 4x =10
y =4x /3+10/3
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9a )
let Xy represent the two digit number
x - y =5 -- -- - (i )
3xy - ( 10x +y 14
3xy - 10 x - y =14 -- - -( ii )
from eqn (i )
x =5+ y
3y ( 5+y ) -10 (5+y )- y =14
15y + 3y ^2 - 50 - 10 y - y =14
3y ^2 + 4 y - 50 = 14
3y ^2 + 4 y - 50 - 14 = 0
3y ^2 + 4 y - 64 =0
3y ^2 + 12 y + 16y - 64 =0
(3y ^2 - 12 y ) (+16 y - 64 )=0
by
(y - 4) +16( y -4 )=0
(y - 4)= 0
ii )
(3y +16) (y - 4)= 0
3y +16 =0 or y - 4=0
3y =- 16 or y =4
y =- 16/3 or y =4
when y =4
x =5+ y
x =5+ 4
x =9
the no is 94
9b)
3- 2x /4 + 2x -3/3
=3( 3-2 x )+4 (2x - 3) /12
=9- 6x +8 x -12 /12
=2x - 2/12
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10a )
y 2x ^2 + 3)^ 5
let U =2x ^2 + 3
Y =u^5
du/dx = 4x
dy /du = 5u^4
dy /du = (2x ^2 + 3)^4
dy /dx = du/dx dy /du
dy /dx = 4x . 5 (2x ^2 + 3)^4
dy /dx = 20x ( 2x ^2 + 3)^ 4
.
10b)
y =3x ^2 + 2x +5
dy /dx =6x + 2
dy /dx =6( 3) +2
dy /dx =18 +2
dy /dx =20
.
10c )
R -W=Wv ^2/gx
Wv ^2=gx (R - W)
Wv ^2=gRx - Wgx
Wv ^2+Wgx =gRx
W(v ^2 + gx ) =gRx
W=gRx /V^2 + gx
R =2, g= 10, x = 3/2, V =3
W= 10 *2*3/2/3 ^2 + 10*3/5
W=30/9 +15
W=30/24
W=5/4
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1a)
Tabulate
x- 1,2,3,4
1- 1,2,3,4
2- 2_, 4, 0_ ,2_
3- 3, 0_, 3, 0_
4- 4_, 2_, 0_, 4
1b)
I = PRT/100,
p=N15000
R=10% and I=3years
A = P+ I where I = 15000*10*3/100=N4500
A=4500+15000 =N19500
2a)
using sine rule
b/sin20 = 6/sin30
bsin30 = 6sin120
b 6sin120/sin30
b = 6x0.2511/0.4540
b = 5.7063/0.4540
b = 12.57 ≠ 12.6cm
2bi)
the diagram is euivalent triangles.
where
|AX|/|BC| = |BY|/|AC| = |XY|/|YC|
XY = 9, BY = 7
YC = 18-7=11
9/11 = 7/|AC|
9|AC| = 77
|AC| = 77/9
|AC| = 8cm
2bii)
XY/AB = BY/AC
9/|AB| = 7/8.6
|AB| = 9x8.6/7
|AB| = 11cm
6 /————————— — / 41.02 × √0.7124 / ———— ———— — — √42.87 × 0.207 × 0.0404
| No | Log |
| 41.02 | 1.6130 | 1.6130
| 0.7124 | T. 8527 ÷ 2 | T.9263/1.5393
| 42.77 | 1.6321 |
| 0.207 | T.3160 |
| 0.0404 | 2. 6064 / |
| | T.5544 | T.5544/1.9849
Antilog = 9658 ≈ 96.58
7a) 3²ⁿ+¹ — 4(3ⁿ+¹) + 9 = 0
3²ⁿ × 3 — 4(3ⁿ× 3¹) + 9 = 0
(3ⁿ)² × 3 — 4(30ⁿ× ) + 9 = 0
Let 3ⁿ= x
3x² — 4 × 3 × x + 9 = 0
3x² — 12x + 9 = 0
Divide all by 3
3x²/3 — 12x/3 + 9/3 = 0
x² — 4x + 3 = 0
x² — 3x — x + 3 = 0
x(x—3) -1(x—3) = 0
(x—3)(x—3) = 0
x—3 = 0 or x—1 = 0
x = 3, x = 1
Substitute x = 3
3ⁿ = 3 or 3ⁿ = 1
3ⁿ = 3¹ or 3ⁿ= 3°
n = 1 or n= 0
3)
let the son age be x
man=5x
son=x
4yrs ago;the man age = 5x - 4
the son age = x - 4
the product of their ages
(5x - 4)(x - 4) =448.
4b)
to fill the tank/volume of fuel needed = 7.5*4.2*1.2 = 37.8m^3 = 37,800
litres addition fuel = 37,800-30,000 = 7,800
litres therefore, 7,800
more litres would be needed
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5a)
sector for building project =48000/144000*360 =120degree
sector for education = 32,000/144000*360=80degree
sector for saving = 19200/144000*360=48degree
sector for maintenance = 12000/144000*360=
30degree
sector for miscellaneous = 7200/144000*360=18degree
sector for food items = 360- (120+80+48+30+18) =360-296 =64degree
5b)
amount spent=144000- [48,000+32000+19200+12000+7200] =144000-118400 =N25600
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