The answer is: (z - 6)(z + 15)
z² + 9z - 90 = z*z + 15z - 6z - 6*15 =
= (z*z + 15z) - (6z + 6*15) =
= z(z + 15) - 6(z + 15) =
= (z - 6)(z + 15)
Answer:
a- x = 5/3, or x = -7/2
b- 675
c - 5·x + 2
Step-by-step explanation:
The polynomial representing the capital of the two partners = 6·x² + 11·x - 35
a. The total share is the capital of the two partners together = 6·x² + 11·x - 35
∴ When their total share is equal to 0, we have;
6·x² + 11·x - 35 = 0
Factorizing the above equation with a graphing calculator gives;
(3·x - 5)·(2·x + 7)
Therefore;
x = 5/3, or x = -7/2
b- The total expenditure, when x = 10 is given by substituting the value of <em>x </em>in the polynomial 6·x² + 11·x - 35, as follows;
When x = 10
6·x² + 11·x - 35 = 6 × 10² + 11 × 10 - 35 = 675
The total expenditure of Vicky and Micky when x = 10 is 675
c - The sum of their expenditure is (3·x - 5) + (2·x + 7) = 5·x + 2
Answer:
-3x^{4} + 19x^{3} - 38x^{2} + 25x - 3
Step-by-step explanation:
1) distribute x² into (-3x² + 7x - 1) to get: -3x^{4} + 7x³ - x²
2) distribute -4x into (-3x² + 7x - 1) to get: 12x³ - 28x + 4x
3) distribute 3 into (-3x² + 7x - 1) to get: -9x² + 21x - 3
4) combine all the answers together into one equation:
-3x^{4} + 7x³ - x² + 12x³ - 28x² + 4x - 9x² + 21x - 3
5) combine like terms:
7x³ + 12x³ = 19x³
-x² + -28x² + -9x² = -38x²
4x + 21x = 25x
6) combine answers together into one equation:
-3x^{4} + 19x³ - 38x² + 25x - 3
