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

Question

Hazel Anglin · Accepted Answer

#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.

Eli Assouline · Answer

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 #

Jameson Allen · Answer

undefined To solve for x: x = -3.4 / 0.4. To check the solution, substitute the value of x back into the original equation: -3.4 = 0.4 * (-3.4 / 0.4).