Answer:
a. x = -9 or x = -2
b. -5(x - 4)
c. x = -3 or x = 5
d. x = ±7
Step-by-step explanation:
a. First person;
y = x² + 11x + 18
y = x² + 9x + 2x + 18
y = x(x + 9) + 2(x + 9)
y = (x + 9)(x + 2)
y = x = -9 or x = -2
b. Second person;
y = -5x + 20
The common factor is 5.
y = -5(x - 4)
c. Third person;
y = x² - 2x - 15
y = x² - 5x + 3x - 15
y = x(x - 5) + 3(x - 5)
y = (x + 3)(x - 5)
y = x = -3 or x = 5
d. Fourth person;
y = x² - 49
Applying the difference of squares formula;
(a² - b²) = (a - b)(a + b)
y = x² - 49 = x² - 7² = (x - 7)(x + 7)
y = (x - 7)(x + 7)
y = x = ±7
Answer:
2.7
3
6
Step-by-step explanation:
2.7×3 = 8.1
3x3=9
6×3= 18
18-8.1= 9.9 < 10
18-9= 9 < 10
18-18=0 < 10
