2,5(3,9x-8y)-1,5(6,5x+y), если x=3; y= - 4,5;

Question

2,5(3,9x-8y)-1,5(6,5x+y), если x=3; y= - 4,5;

Answer 1

2.5(3.9х - 8у) - 1.5(6.5х +у) = 9.75х - 20у - 8х - 1.5у = 1.75х - 21.5у.
х = 3; у = -4.5 
1.75 ×3 - 21.5×(-4.5) = 5.25 + 96.75 = 102.