Answer:
x = -80
Step-by-step explanation:
[tex]\frac{1}{2}(x-10)=\frac{3}{4}(x+20)\\\\\\\frac{1}{2}x-\frac{1}{2}*10=\frac{3}{4}x+\frac{3}{4}*20\\\\\\\frac{1}{2}x-5=\frac{3}{4}x+3*5\\\\\\\frac{1}{2}x-5=\frac{3}{4}x+15\\\\\\\frac{1}{2}x-5-15=\frac{3}{4}x\\\\\\\frac{1}{2}x-20=\frac{3}{4}x\\\\\\-20=\frac{3}{4}x-\frac{1}{2}x\\\\\\-20=\frac{3}{4}x-\frac{1*2}{2*2}x\\\\\\-20=\frac{3}{4}x-\frac{2}{4}x\\\\\\-20=\frac{1}{4}x\\\\\\-20*4=x\\\\\\x = -80[/tex]