Step by step
The question
Question: solve 5x = −35.
5x = −35
There are four choices.
First we solve it, the normal way.
Then we pick.
1 Remove the 5
5x means 5 times x.
We want just x.
To remove times 5, we divide by 5.
We do it on both sides.
Why both sides?
The = sign means both sides are the same amount.
If we change only one side, they are not the same any more.
5 divided by 5 is 1.
So just x is left.
−35 divided by 5 is −7.
−355 = −7
So x = −7!
x = −7
2 Check
Let's check: put −7 in place of x.
Check: 5(−7) = −35
We get −35, the same as the right side.
So x = −7 is right!
3 Pick the choice
Our answer is x = −7.
That is choice C.
C) −7
4 Why not the others
A is −175.
Wrong: −35 × 5: multiplied instead of dividing.
A) −175 ✗ −35 × 5: multiplied instead of dividing
B is −40.
Wrong: −35 − 5: took away 5.
B) −40 ✗ −35 − 5: took away 5
D is 7.
Wrong: lost the minus sign.
D) 7 ✗ lost the minus sign
Let's look back.
First: remove the 5.
Then: check.
Then: pick the choice.
Last: why not the others.
Answer
x = −7