To solve this, we first need to substitute the value of y in terms of x from the given equation x+y=3.
Given x+y=3, solving for y we get y=3-x.
Now, substitute this value of y in the expression 6×(3x+5x)+7×-5y:
6×(3x+5x)+7×-5y = 6×(8x)+7×(-5(3-x))= 48x-35(3-x)= 48x-105+35x= 83x-105
Therefore, the simplified expression is 83x-105.
To solve this, we first need to substitute the value of y in terms of x from the given equation x+y=3.
Given x+y=3, solving for y we get y=3-x.
Now, substitute this value of y in the expression 6×(3x+5x)+7×-5y:
6×(3x+5x)+7×-5y = 6×(8x)+7×(-5(3-x))
= 48x-35(3-x)
= 48x-105+35x
= 83x-105
Therefore, the simplified expression is 83x-105.