Question

Make x the subject of these equations.

Answer 1

$(1)a(x + b) = c \\ ax + ab = c \\ ax = c - ab \\ \frac{ax}{a } = \frac{c - ab}{a} \\ x = \frac{c - ab}{a}$

$(2)8(x + a) = b \\ 8x + 8a = b \\ 8x = b - 8a \\ \frac{8x}{8} = \frac{b - 8a}{8} \\ x = \frac{b - 8a}{8}$

$(3)a(x - 7) = b \\ ax - 7a = b \\ ax = b + 7a \\ \frac{ax}{a} = \frac{b + 7a}{a} \\ x = \frac{b + 7a}{a}$

$(4)c(2 + x) = 6 \\ 2c + cx = 6 \\ cx = 6 - 2c \\ \frac{cx}{c} = \frac{6 - 2c}{c} \\ x = \frac{6 - 2c}{c}$

Answer 2

A(x+b)=c
Open bracket: ax+ab=c
ax=c-ab
Divide both sides by a to make x subject of formula
x=c-ab/a
x=c-b

8(x+a)=b
8x+8a=b
8x=b-8a
x=b-8a/8
x=b-a

a(x-7)=b
ax-7a=b
ax=b+7a
x=b+7a/a
x=b+7

c(2+x)=6
2c+cx=6
cx=6-2c
x=6-2c/c
x=6-2
x=4