Algebra with Area

Multiplying Binomials

100

Multiply

(x + 5)(x - 9)

x² -4x - 45

200

Multiply

(3x - 7)(5x + 8)

15x² -11x -56

300

Multiply

(x - 6)²

x² - 12x + 36

400

Multiply

(8x-5)(8x+5)

64x² -25

500

Multiply

(5x - 8y)²

25x² - 80xy + 64y²

Factor Trinomials

100

Factor

x² + 8x + 12

(x+2)(x+6)

200

Factor

x² + 4x - 5

(x+5)(x-1)

300

Factor

x² - 18x + 81

(x-9)(x-9)   or (x-9)²

400

Factor

x² - 144

(x+12)(x-12)

500

Factor

100x² - 81

(10x+9)(10x-9)

Area problems

100

The area of a rectangle is equal to 50. The length is equal to 4x, and the width is equal to 8x. Find x.

x = 1.25

200

The area of a triangle is equal to 100. The base is equal to 5x + 2 and the height is equal to 8. Find x.

x = 4.6

300

The area of a circle is equal to 1225pi square cm. The radius is equal to 5x. Find x. 

x = 7

400

The area of a trapezoid is equal to 72 square cm. 

b1 = 5x,  b2 = 7x  and h = 8.  Find x. 

x = 1.5

500

The area of an annulus is equal to 64pi square cm. 

The radius of the larger circle is equal to 5x and the radius of the smaller circle is equal to 3x

x = 2