Answer:
Step-by-step explanation:
The system of equations is given as
y=x^2-5x+7 - - - - - - - - - - 1
y=2x+1 - - - - - - - - - - - - - - 2
We would equate equation 1 to equation 2, it becomes
x^2-5x+7 = 2x+1
x^2-5x+7- 2x - 1 = 0
x^2-5x+7- 2x - 1 = 0
x^2 - 5x - 2x + 7 - 1 = 0
x^2 - 7x + 6 = 0
We would use the factorization method of solving quadratic equations.
x^2 - 6x - x + 6 = 0
x(x - 6) - 1(x - 6)
(x - 6)(x - 1) = 0
x - 6 = 0 or x - 1 = 0
x = 6 or x = 1
Substituting both values of x into equation 2, it becomes
For x = 6,
y=2×6 + 1 = 12 + 1 = 13
y = 13
For x = 1,
y=2 × 1 +1 = 2 + 1 = 3
y = 3
Answer:
4 and 9
Step-by-step explanation:
let their ages be x and x - 5, then in 4 years their ages will be
x + 4 and x - 5 + 4 = x - 1 , and the product is 104, thus
(x + 4)(x - 1) = 104 ← expand factors on left using FOIL
x² + 3x - 4 = 104 ( subtract 104 from both sides )
x² + 3x - 108 = 0 ← in standard form
(x + 12)(x - 9) = 0 ← in factored form
Equate each factor to zero and solve for x
x + 12 = 0 ⇒ x = - 12
x - 9 = 0 ⇒ x = 9
However, x > 0 ⇒ x = 9
Thus
Their present ages are 9 and 9 - 5 = 4
Answer: 11, 45, 45, 54, 520
2.
you had nothing for 1. and I am not sure what you mean by 4.
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