8x – 8 = 7x + 4 x = 12 how do they get 12?

Hello from MrBillDoesMath!

See Discussion below

Discussion:

8x - 8 = 7x + 4               =>   add 8 to both sides

8x - 8 +8 = 7x + 4 + 8    =>  as 4+8 = 12

8x = 7x + 12                    => subtract 7x from each side

8x -7x  = 7x -7x + 12       => 7x - 7x = 0, 8x - 7x = x

x = 0 + 12 = 12

Thank you,

MrB

x = 12 Correct

Step-by-step explanation:

8x - 8 = 7x + 4

subtract variable 7x since its the smallest aswell as subtract variable 7x from 8x

we now have 1x - 8 = 4

to get rid of negative numbers we add, so add +8 to the -8 and the equals 4

we now have 1x=12

divide variable 1x by itself but only the number and the equals12

1x divided by 1 equals x and 12 divided by 1 equals 12

so your left with 12.

  21.3

step-by-step explanation:

multiplying the given equation by c/sin(25°), we get

  c = 9/sin(25°) ≈ 21.2958 ≈ 21.3

we assume "c" is the length of ab, the side opposite angle c in triangle abc.

both equations and proportions are better.