<h2>Answer:</h2>
Number of biology textbooks sold: 257 textbooks
Number of psychology textbooks sold: 181 textbooks
<h2>Explanations:</h2>
Let the total number of biology textbook sold be "a"
Let the total number of psychology textbook sold be "b"
If a textbook store sold a combined total of 438 biology and psychology textbooks in a week, then:
a + b = 438 ................... 1
If the number of psychology textbooks sold was 76 less than the number of biology textbooks sold, then;
b = a - 76 ...................... 2
Substitute equation 2 into 1
a + (a-76) = 438
a + a - 76 = 438
2a = 438 + 76
2a = 514
a = 514/2
a = 257 biology textbooks
From equation 2;
b = a - 76
b = 257 - 76
b = 181 psychology textbooks
Number of biology textbooks sold: 257 textbooks
Number of psychology textbooks sold: 181 textbooks
Answer:
x^2 - 8xy + 3y^2 - 2
Step-by-step explanation:
(-8xy + 2x^2 + 3y^2) - unknown = x^2 + 2
- unknown = x^2 + 2 + 8xy - 2x^2 - 3y^2
- unknown = -x^2 + 8xy - 3y^2 + 2
Unknown = x^2 - 8xy + 3y^2 - 2
Check:
(-8xy + 2x^2 + 3y^2) - (x^2 - 8xy + 3y^2 - 2)
= -8xy + 2x^2 + 3y^2 - x^2 + 8xy - 3y^2 + 2
= -8xy + 8xy + 2x^2 - x^2 + 3y^2 - 3y^2 + 2
= x^2 + 2
Answer: The area of triangle ΔXYZ is 12 square inches.
Step-by-step explanation:
Since we have given that
RS = 3 inches
XY = 2 inches
Area of ΔRST = 27 in²
Since ΔRST is similar to ΔXYZ.
So, using the "Area similarity theorem":

Hence, the area of triangle ΔXYZ is 12 square inches.
Answer:
sorry I need points
Step-by-step explanation:
so so sorry
Answer:
The statistical relationship between two variables is referred to as their correlation. A correlation could be positive, meaning both variables move in the same direction, or negative, meaning that when one variable's value increases, the other variables' values decrease.
Step-by-step explanation: