gr 10 math
posted by Rebecca .
Solve using the quadratic formula.
a) x^2  7x + 12 = 0
a = 1 b = 7
x = b +/ the sr of b^2  4ac /2a
7 +/ the sr of 7^2  4(1)(12) /2a
7 +/ the sr of 49  48 /2a
7 +/ the sr of 97 /2a
7 +/ 97 /2a
90/2=45
104/2= 54
The roots are 45 and 54.
did i solve this correctly?

x^2  7x + 12 = 0
The 12 can factor into 3 and 4 to add to 7 in the middle term.
(x3)(x4) = 0
x = 3 or 4.