Verified answer

7(5-х) - 3(х+4) = 63

35 - 7х - 3х - 12 = 63

23 - 10х = 63

-10х = 63 - 23

-10х = 40

х = -4

[tex]7(5 - x) - 3(x + 4) = 63 \\ 35 - 7x - 3x - 12 = 63 \\ - 10x + 23 = 63 \\ - 10x = 63 - 23 \\ - 10x = 40 \\ x = 40 \div ( - 10) \\ x = - 4[/tex]