Factorise, check by using multiplication a-7a+12​

Step-by-step explanation:

Sum = -7

Product = 12

Factors = (-3) ; (-4)   { (-3) * (-4) = 12  and (-3) + (-4) = -7}

a² - 7a + 12 = a² -3a    - 4a + (-3)(-4)

                 = a(a - 3) - 4(a - 3)

                 = (a - 3)(a - 4)

rectangle: 9 1/8 x 4 1/9 = 37 37/72in

parallelogram: b times h= 10.3 x 6.2 = 63.86

trapezoid: a+b/2 times h= 42.5

volume of prism: l times w times h= 36

c

step-by-step explanation: