Question

add: 5x^2+7y-8,4y+7-2x^2 and 6-5y+4x^2

Answer 1

so, the three expressions are

$5x^2 + 7y - 8 \\4y + 7 - 2x^2 \\and \\6-5y + 4x^2$

when getting them together we'll get,

$(5x^2 + 7y - 8) + (4y + 7 - 2x^2) + (6-5y + 4x^2)$

now we combine like terms

$5x^2 - 2x^2 + 4x^2 + 7y + 4y - 5y - 8 +7 + 6$

now we add/subtract the like terms.

$7x^2 + 6y + 5$

which is our final answer because there are no more like terms left to combine.