Earlyface

Neco Mathematics*
No6
i)7+8+x*x=47
15+2x=47
2x=47-15
2x/2 =32/2
x=16//
ii) Tram only
7+8+3+y =30
18+y =30
y=30-18=12
.Tram only =12//
iv) 16+7+12+16+8+3+9=95
62+9=95
9=95-62
9=33// or car only =33
iii)at least two
7+16+3+8
=34//
====================
6i)
7+8+x = 47
15+ 2x =47
2x = 47- 15
2x/2 = 32/2
divide both side by 2
x=16
6ii)
tran only;:
7+8 + 3 + y=30
18 +y =30
y=30 -18 =12
:. Tran only =12
iii) at least two: 7+ 16+ 3 +8 =34
iv)16 + 7 +12 +16 +8 + 3 + Q=95
62+ Q =95
Q= 95 -62
Q=33 :. Car only = 33
*NECO MATH*
8ai)
y=(4x+9)^3
let u =4x+9, y=U^3
du/dx=4, dy/du=3U^2
dy/dx=dy/du * du/dx = 4*3u^2=12u^2
recall= U=4x+9
dy/dx=12(4x+9)^2
8aii)
y=(3x-2)^3 (x^2 + 4)^2
u=(3x-2)^3 V=(x^2+4)^2
du/dx=3.3(3x-2)^3-1 , dv/dx=2x.2(x^2+4)^2-1
=4x(x^2+4)
in other words
dy/dx=Vdu/dx + udv/dx
=(x^2+4)^2 9 (3x-2)^2+(3x-2)^3 4x(3x-2)
=(x^2+4) (3x-2)^2 (9x^2+36+12x^2-8x)
=(x^2+4) (3x-2)^2 (21x^2-8x+36)
8b)
y-y1=m(x-x1)
y-6=2(x-2)
y-6=2x-4
y=2x-4+6=2x+2
*2021 NECO MATH*
*11a)*
Tabulate
X- |-1| |0| |1| |2| |3| |4|
6 |6| |6| |6| |6| |6| |6|
+X |-1| |0| |1| |2| |3| |4|
-X^2 |-1| |0| |-1| |-4| |-9| |16|
Y- |4| |6| |6| |4| |0| |-6|
*2021 Neco Math Answer*
12a)
From Equation 1
3x + 2y – 12
3x+2y=90+12
3x+2y=102…(1)
sum of angle in a circle = 360 degree
5x+y-9+3x+2y-12+3y+4x+21=360
5x+3x+4x+y+2y+3y-9-12+21=360
12x+6y=360….(2)
Solving equation (1) and (2) simultaneously
3x+2y=102
12x+6y=360