Answer:
x=6
Step-by-step explanation:
(x^2 – 3x - 10) = (x + 2)
Factor the term on the left
(x-5) (x+2) =x+2
Divide each side by x+2
x-5 = 1
Add 5 to each side
x-5+5 =1+5
x=6
Answer:
(-10, 10) and (0,10).
Step-by-step explanation:
For a point to be a solution to the system of inequalities, you will need to see which of the points falls into the shaded area.
When we test out each of the points, we can see that only:
(-10, 10) and (0,10) fall into the blue-shaded area.
Hi there!
So for #1:
-12>-36-8x
+36 to both sides of the inequality
24>-8x
Divide both sides by negative 8
Note: when you divide by a negative number, the inequality changes direction.
So you end up with -3-3
For the other two, you forgot to include y and t, so I can't help solve those yet.
Answer:
700 lei
Step-by-step explanation:
You have a geometric sequence for which you know the common ratio and the last term.
There are only three terms, so you can solve the problem in either of two ways.
1. The brute force method
(easiest for only a few terms)
Each term is half the one before it, so each term is double the one after it.
3rd term = 100 lei
2nd term = 200
1st term = 400
Total = 700 lei
Oana spent 700 lei
2. Using formulas (best for longer sequences)
The general formula for your sequence is
aₙ = a₁rⁿ⁻¹
For your sequence,
a₃ = 100; r = 0.5
(a) Calculate a₁
Set the last term equal to the general formula.
a₃ = a₁(0.5)ⁿ⁻¹
100 = a₁(0.5)² = 0.25a₁
a₁ = 100/0.25 = 400
(b) Calculate the sum
The general formula for the sum of a geometric sequence is
Oana spent 700 lei.