Answer:176 psychology textbooks and 98 Biology textbooks were sold.
Step-by-step explanation:
Let x represent the number of psychology textbooks that were sold.
Let y represent the number of biology textbooks that were sold.
textbook store sold a combined total of 274 psychology and biology textbooks in a week. This means that
x + y = 274 - - - - - - - - - - -1
The number of psychology textbooks sold was 78 more than the number of biology textbooks sold. This means that
x = y + 78
Substituting x = y + 78 into equation 1, it becomes
y + 78 + y = 274
2y = 274 - 78
2y = 196
y = 98
x = y + 78 = 98 + 78
x = 176
Answer:
Stated below:
Step-by-step explanation:
You can't change your Brainly username unless you want to make a new account.
Answer:
x = 5
Please tell me if im incorrect and hope this helped ^^
Answer:
B.
Step-by-step explanation:
First we must find the x and y intercepts for y = -2x - 4. The y-intercept is -4, since it is b in y = mx + b, but you can also find it by plugging in zero for x:

The x-intercept is found by plugging in zero for y:





The graph with an x-intercept of -2 and a y-intercept of -4 is C. Also, less than inequalities have the shading underneath the line, so we definitely know C is the answer.
This is the formula to solve for the vertex.
Example Question:
Find the vertex of y = -0.5x^2 + 100x
-b/2a = -100/2(-0.5) = -100/-1 = 100
The x coordinate of the vertex is 100.
Best of Luck!
P.S. this is 1000th question i've answered :)