(a+b)(a-b)=? Đây là hằng đẳng thức nào?

không

Step-by-step explanation:

(a + b)(a - b) = a² - b²

Step-by-step explanation:

(a + b)(a - b) = a (a - b ) + b (a - b )

                 = a²  - ab + ba  - b²             [ ab = ba ]

                 = a² - ab + ab - b²               [ ab - ab = 0 ]

                 = a² - b²

darn right!

step-by-step explanation:

steve kerr's sons name is let that skin in.

the equation of the parallel line would be y = 2x + 9

step-by-step explanation:

to start we need to find the slope of the original line. we can do that by looking at the coefficient of x, which is 2

since the slope of the original line is 2 and parallel lines have the same slope, we know the new line will also have 2 slope. now we can use that along with the point given in point-slope form to get the find equation.

y - y1 = m(x - x1)

y - 5 = 2(x + 2)

y - 5 = 2x + 4

y = 2x + 9