How do you evaluate #2x^2 - 2z^4 + y^2 - x^2 + z^4# if #x = -4, y = 3, and z = 2#?

1 Answer
Jun 30, 2016

Answer:

#9#

Explanation:

Given,

#2x^2-2z^4+y^2-x^2+z^4#

Knowing that #x=-4, y=3, z=2#, replace each variable with its appropriate number.

#=2(-4)^2-2(2)^4+(3)^2-(-4)^2+(2)^4#

Recall that a number raised to a power #n# means to multiply the number by itself #n# times. Hence,

#=2(color(red)(-4)*color(red)(-4))-2(color(blue)2*color(blue)2*color(blue)2*color(blue)2)+(color(darkorange)3*color(darkorange)3)-(color(purple)(-4)*color(purple)(-4))+(color(teal)2*color(teal)2*color(teal)2*color(teal)2)#

Simplify.

#=2(color(red)16)-2(color(blue)16)+(color(darkorange)9)-(color(purple)16)+(color(teal)16)#

#=32-32+9-16+16#

#=color(green)(|bar(ul(color(white)(a/a)color(black)9color(white)(a/a)|)))#