The easiest way is to use (& to memorize) the sum formula for a AP:

Sum = 1st term added to the last term & multiplied by half the number of terms
S = (a+l)n/2

S = (5 + 53)(7/2) = 203

5 0

4 years ago

Given f(x)=3x-2 and g(x)=5x, what is f(x)•g(x)

Natasha2012 [34]

F(x)·g(x) = (3x-2)(5x) = 15x^2 -10x

6 0

3 years ago

Demi has 21 baseball cards and 13 football cards.

djyliett [7]

Answer:

Step-by-step explanation:

21+13+19+36=89

6 0

3 years ago

Which of the following are the coordinates of the vertex of y = −x2 + 2x + 1? (2, 1) (1, –2) (1, 2) (–2, 1)

IceJOKER [234]

Answer:

Step-by-step explanation:

We want to determine the vertex of the quadratic equation:

$\displaystyle y = -x^2 + 2x + 1$

Recall that the vertex is given by the formulas:

$\displaystyle \text{Vertex} = \left(-\frac{b}{2a}, f\left(-\frac{b}{2a}\right)\right)$

In this case, a = -1, b = 2, and c = 1.

Determine the x-coordinate of the vertex:

$\displaystyle x = -\frac{(2)}{2(-1)} = 1$

To determine the y-coordinate, evaluate the function at x = 1:

$\displaystyle \begin{aligned} y(1)&= -(1)^2 + 2(1) + 1 \\ &= 2\end{aligned}$

In conclusion, the vertex of the quadratic equation is (1, 2).

Hence, our answer is C.

3 0

3 years ago