How do you solve and check your solution given $-3.4=0.4x$ ?

Question

4130 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-01-07T22:02:33

$x = -8.5$
... see below :)

When it says to solve, it means to find what the unknown variable equals to. So you want to isolate x to find what x is.

$-3.4=0.4x$

$-3.4/0.4=(0.4x)/0.4$

$-8.5=x$

To check if what we got is correct, we can input the answer back into the equation. So since we found that x=-8.5, we want to replace x with -8.5

$-3.4=0.4x$

$-3.4=0.4(-8.5)$

$-3.4=-3.4$

The left side is equal to the right side, so therefore we know that our answer is correct.

Answer 2 · 2018-01-07T22:05:33

Find a value for $x$ and then substitute it back into the original equation to see if it is true.

We are told $-3.4 = 0.4x$

Therefore, to begin, we need find a value for $x$ . To do this we simply divide by the coefficient in front of $x$ , in this case $0.4$

$therefore$ $(-3.4/0.4) = x$

$therefore x =-17/2$

To check we substitute the values of $x$ back into the original equation to see if it is true.

Subbing $-17/2$ we get $-3.4 = 0.4(-17/2)$

which $-3.4 = -3.4$

How do you solve and check your solution given -3.4=0.4x-3.4=0.4x?