Question

Can someone please help me with these 2 problems PLEASE????????
1) 1) Simplify the algebraic expression
5xy - 3yz - 5xz + yz - 4xz + 7xy and evaluate it for x = 10, y = -4, z = -6.
Identify the variables, constants, and coefficients in the simplified expression.

Answer 1

add like terms first. Later substitute x,y,z values

Answer 2

so would it be
5xy - 3yz - 5xz + yz - 4xz + 7xy
5 *10*4 -3*4*6 – 5*10*6 + 4*6- 4*10*6+ 7*10*4
50*4- 12*6- 50*6+24-40*6+70*4
200-72-300+24-240+280
128-324-520
128-196=68