\[\sum_{n=1}^{7} 2(-2)^{n-1}\]
Answer:
A
12+7x=a
x=days
a=amount of money
B 12+7x=a
Step-by-step explanation:
7(18)=126
12+126=a
138=a
First, solve the inequality:
Since x is <u>greater than</u> -8, you have the arrow point up the graph towards the positive side starting at -8.
Since it's greater than but not equal to -8, the circle is open.
Thus your graph is
D.
Answer:
The answer is below
Step-by-step explanation:
Let x represent the cost of 1 scoop of ice cream. Since the cost of 2 scoops of ice cream are twice the price of 1 scoop of ice cream, therefore the cost of 2 scoops of ice cream = 2x
Jean buys 4 tubs with 2 scoops in them and 2 tubs with 1 scoop each. Therefore the money spent by Jean is:
Money spent by Jean = 4(2x) + 2(x) = 8x + 2x = 10x
Sarah buys 2 tubs of 2 scoops and 4 tubs of 1 scoop. The money spent by Sarah is:
Money spent by Sarah = 2(2x) + 4(x) = 4x + 4x = 8x
Sarah spends 2.50 € less than Jean. Therefore:
Money spent by Sarah = Money spent by Jean - 2.5
8x = 10x - 2.5
2x = 2.5
x = €1.25
Therefore the cost of 1 scoop of ice cream is €1.25, the cost of 2 scoops of ice cream is €2.50.
Money spent by Jean = 10x = 10(1.25) = €12.5
Money spent by Sarah = 8x = 8(1.25) = €10
7) Use distributive property
3x(4x⁴ - 5x)=3x*4x⁴- 3x*5x = 12x⁵ - 15x²
8) When you open parenthesis with minus sigh in front of it, you need change sings of the terms on opposite. Then find like terms.
(5x⁴-3x³+6x)-(3x³+11x²-8x)= 5x⁴-3x³+6x -3x³-11x²+8x =5x⁴-6x³ - 11x²+14x
9)(x-2)(3x-4)=x*3x-4x-6x+8=3x²-10x+8
10) (x+6)²=(x+6)(x+6)=x²+6x+6x+36=x²+12x+36
For (x+6)², you can also use the formula of the perfect square
(a+b)²=a²+2ab+b²
For (x+6)² =x²+2*x*6 +6²=x²+12x+36
