algebra 2a - unit 1: exam

which expression represents the number 3 + √-4 rewritten in a + bi form?

3 + 2i

what are the solutions of the equation (x + 16)^2 = 28?

x = -16 ± 2√7

marcus used the quadratic formula, to solve the equation 0 = x^2 + 5x + 17 as follows. did marcus make a mistake? if so, where?

yes, in step 1, he should have written 2(1) instead of 2(5) because a = 1.

solve the quadratic equation x^2 + 3x - 10 = 0 by completing the square. what is the solution, or what are the solutions, to the equation?

2, -5 (it says it's wrong on the test when it is right? it don't make sense) (maybe space the numbers)

which expression is equivalent to (2 - √-4) + (1 + √-49)?

3 + 5i

what is the factored form of the expression 9x^2 - 24x + 16?

(3x - 4)^2

what is the factored form of the expression x^2 + 13x + 42?

(x + 6)(x + 7)

which expression represents the number 2i^4 - 5i^3 + 3i^2 + √-81 rewritten in a + bi form?

-1 + 14i

which expression is equivalent to 4i(3 + 9i)?

-36 + 12i

which expression represents the number 2 + 5i - i(3 - 6i) rewritten in a + bi form?

-4 + 2i

what are the zeros of the function f(x) = x^2 + 8x + 16?

-4 only

which expression is equivalent to (4 + 6i)(2 + 8i)?

-40 + 44i

for the number 18, what is the value of a and b?

a = 18 and b = 0

which simplifications of the powers of i are correct? select all that apply.

i^7 = -i i^16 = 1

anna solved the equation (x + 4)^2 = 2 using the following steps. which statement identifies a mistake anna made, if any?

she did not make a mistake. her answer is correct.

given the complex numbers l and m below, what is l - m? l = 3 + 8i m = 2 - 14i

1 + 22i

which expression is equivalent to (2 - 3i) + (2 + 7i)?

4 + 4i

what are the solutions to the equation x^2 + 3x - 28 - 0?

4, -7

which expression is equivalent to (2 - 7i) - (-3 + 2i)?

5 - 9i

which expression or value is equivalent to (8 + 2i)(8 - 2i)?

68

use the quadratic formula, to solve the equation 5x^2 + 8x + 1 = 0. match each step to the correct method for solving the equation.

step 1: x = -8 ± √8^2 - 4(5)(1) / 2(5) step 2: x = -8 ± √64 - 20 / 10 step 3: x = -8 ± √44 / 10 step 4: x = -8 ± 2√11 / 10 step 5: x = -4 ± √11 / 5

lupita completed the square to solve the equation 0 = x^2 - 6x + 13 as follows. did lupita make a mistake? if so, where did the mistake occur, and what was it?

yes, in step 3, she should have added 9 to both sides of the equation.