7/8x = -21
Mutiply both sides by 8/7
7/8(8/7)x= -21(8/7)
Cross out 7 and 7, divide by 7 and then becomes 1.
Cross out 8 and 8 , divide by 8 and 8 then becomes 1.
1*1*x=x
Cross out -21 and 7 , divide by 7. -21/7=-3
7/7= 1
-3*8= -24
Answer: x=-24
