Answer:
The number of textbooks of each type were sold is <u>134 math </u>and <u>268 psychology </u>books.
Step-by-step explanation:
Given:
Total number of math and psychology textbooks sold in a week is 402.
Now, let the number of math textbooks sold be
.
And, the number of psychology textbooks be
.
According to question:


Dividing both sides by 3 we get:

So, total number of math textbooks were 134 .
And, total number of psychology textbooks were 
.
Therefore, the number of textbooks of each type were sold is 134 math and 268 psychology books.
*Hint: In order to find the coordinates, you plug in the coordinates into the rule and solve.
(x, y) → (x + 2, y - 8)
(4, -5) → (4 + 2, -5 - 8)
(6, -13)
The coordinates of B' is (6, -13).
X + (7 - 3i) + (5 + 9i) + 13i = 10 - 5i
Subtract 13i from both sides
x + (7 -3i) + (5 + 9i) = 10 - 18i
Subtract (5 + 9i). MAKE SURE YOU SUBTRACT 9i TOO. In other words, distribute the negative and subtract 5 and 9i at the same time.
x + (7 - 3i) = 5 - 27i
Do the same with (7 - 3i). You'll be adding 3i since -(-3i) = 3i.
x = -2 - 24i