1. a^2 + 7a + 10 = 0
(a + 5)(a + 2) = 0
a + 5 = 0....a = -5
a + 2 = 0...a = -2
solution : (-2,-5)
2. n^2 - 8n + 12 = 0
(n - 2)(n - 6) = 0
n - 2 = 0....n = 2
n - 6 = 0...n = 6
solution : (2,6)
3. y^2 - 49 = 0
y^2 = 49
y = sqrt 49
y = (+-) 7
y = 7
y = -7
solution : (-7,7)
4. x^2 + 5x - 6 = 0
(x+ 6)(x - 1) = 0
x + 6 = 0...x = -6
x - 1 = 0...x = 1
solution : (-1,1)
5. u^2 - 7u - 18 = 0
(u - 9)(u + 2) = 0
u - 9 = 0...u = 9
u + 2 = 0....u = -2
solution : (-2,9)
6. m^2 - 5m = 0
m(m - 5) = 0
m = 0
m - 5 = 0...m = 5
solution : (0,5)
7. 2t^2 + 5t - 3 = 0
(2t - 1)(t + 3) = 0
2t - 1 = 0...2t = 1...t = 1/2
t + 3 = 0...t = -3
solution : (1/2,-3)
8. 3w^2 -8w + 4 = 0
(3w - 2)(w - 2) = 0
3w - 2 = 0...3w = 2...w = 2/3
w - 2 = 0....w = 2
solution : (2/3,2)
9. 2x^2 -3x - 5 = 0
(2x - 5)(x + 1) = 0
2x - 5 = 0...2x = 5...x = 5/2
x + 1 = 0....x = -1
solution : (5/2,-1)
10. 5v^2 + 29v + 20 = 0
(5v + 4)(v + 5) = 0
5v + 4 = 0...5v = -4...v = - 4/5
v + 5 = 0....v = -5
solution : (-4/5,-5)
11. 6n^2 - 19n + 15 = 0
(3n-5)(2n-3)=0
3n-5 = 0...3n = 5...n = 5/3
2n - 3 = 0....2n = 3...n = 3/2
solution : (5/3,3/2)
12. 2k^2 + 7k = 0
k(2k+7) = 0
k = 0
2k+7 = 0...2k = -7...k = -7/2
solution : (0,-7/2)
13. 3b^2 + b - 10 = 0
(3b-5)(b+2) = 0
3b - 5 = 0....3b = 5..b = 5/3
b + 2 = 0...b = -2
solution :(5/3,-2)
14. 4y^2 -25 = 0
4y^2 = 25
y^2 = 25/4
y = sqrt 25/4
y = (+-) 25/4
y = 2.5
y = -2.5
solution : (2.5,-2.5)