What is the standard form of y= (x + 2)(x + 5)?

2 Answers
Alan P.
Dec 1, 2015

y=x^2+7x+10

Explanation:

The "standard form" for a quadratic is (in general)
color(white)("XXX")y=ax^2+bx+c
with constants a, b, and c

Tony B
Dec 1, 2015

y=x^2+7x+10
Look at the method. It is using something called the 'Distributive' law

Explanation:

Given y= (color(green)(x)color(red)(+)color(blue)(2))(x+5)

y=color(green)(x)(x+5) color(red)(+)color(blue)(2)(x+5)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Notice that the sign of the color(blue)( 2) follows it.
If the sign had been negative then we would have color(red)(-)color(blue)(2)(x+5)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
y=(color(green)(x) xx x)+(color(green)(x) xx5)color(white)(....)+color(white)(....)(color(blue)(2) xx x)+(color(blue)(2)xx5)

y=x^2+5x+2x+10

y=x^2+7x+10

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