Answer:
(5, 3 ) and (- , - 10 )
Step-by-step explanation:
Given the 2 equations
2x - y = 7 → (1)
xy = 15 → (2)
Rearrange (1) expressing y in terms of x , that is
y = 2x - 7 → (3)
Substitute y = 2x - 7 into (2)
x(2x - 7) = 15
2x² - 7x = 15 ( subtract 15 from both sides )
2x² - 7x - 15 = 0 ← in standard form
(x - 5)(2x + 3) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 5 = 0 ⇒ x = 5
2x + 3 = 0 ⇒ 2x = - 3 ⇒ x = -
Substitute these values into (3) for corresponding values of y
x = 5 : y = 2(5) - 7 = 10 - 7 = 3 ⇒ (5, 3 )
x = - : y = 2(- ) - 7 = - 3 - 7 = - 10 ⇒ (- , - 10 )
80 degrees because it decreases by a half each time so by the time it is E (the fourth letter) it has gotten to 20 so the answer is 160
Answer:
-14
Step-by-step explanation:
First of all, we know that 5x^2+ ax+7x +5=0 only has one root. That means that b^2 - 4ac=0, and we can use this to find the discriminant, ax + 7x.
Now, if we simplified 5x^2+ ax+7x +5=0, by dividing it all by 5, it would be x^2+(a+7)/5x + 1 = 0.
After, we can plug what we know into the formula, b^2 - 4ac=0. It would be:
(a+7)^2 / 25 - 4 = 0
(a+7)^2 / 25 = 4
(a+7)^2 = 100
Since this is a square root, a+7 can be both negative or positive.
a+7= 10, or a+7 = -10
a=3, or a=-17
The question asks for the sum of a, which is 3 + (-17) = -14
Therefore, the answer is -14.
:) have fun with your rsm problems, assuming you got this from the portal.
Answer:
16>2.3b
Step-by-step explanation:
1.5+0.8=2.3
Substitute b as 1. Which would still keep it as 2.3.
Answer:
Can you give me the choices for each of these, I'm not sure how they might phrase it.