Question

Use substitution to show that 9+ 6(10-7x) is equivalent to 69-42x.

Answer 1

9 + 60 -42x
9+60 = 69
= 69- 42x

Answer 2

Answer: 9 + 6(10- 7x) = 69 - 42x

Explanation:

9 + 6(10- 7x)

we open the bracket first

9 + 60 - 42x

69 - 42x

Therefore the two equations are equivalent

we can also check by substituting a number, lets say x = 1

9 + 6[10 - 7(1)] = 69 - 42(1)

9 + 18 = 69 - 42

27 = 27