Question

Find the sum of:
(v) $5x^2-2xy+3y^2,-2x^2+5xy+9y^{2}and3x^2-xy-4y^2$

Answer 1

Step: Find the sum of given expressions
We need to find sum of $(5x^2-2xy+3y^2)$, $(-2x^2+5xy+9y^2)$ and $(3x^2-xy-4y^2)$ $=(5x^2-2xy+3y^2)+(-2x^2+5xy+9y^2)+(3x^2-xy-4y^2)$ $=(5x^2-2x^2+3x^2)+(-2xy+5xy-xy)+(3y^2+9y^2-4y^2)$ [Grouping like terms] $=(3x^2+3x^2)+(3xy-xy)+(12y^2-4y^2)$
$=6x^2+2xy+8y^2$
Hence, the answer is$=6x^2+2xy+8y^2$.