Answer:
Step-by-step explanation:
follow the Pemdas order of operations
add and subtract (left to right)
apply the rule +(-a)=-a
+(-78)=-78
=54-78-(-39)
54-78=-24
=-24-(-39)
apply the rule -(-a)=+a
-(-39) =+39
=-24 +39
-24+39=15
=15
Answer:
i think it's the third one
Answer:

Step-by-step explanation:
y = f(x)
y = 2x+3
You need to switch the places of x and y, into this:
x = 2y + 3
Then solve for y:
2y = x-3


Since this is out of 4, you can think of 4 as being 1. Now each part of 4 needs to have an equal value so you need to split 1 into 4 equal values. So half of 1 is 0.5 and half of 0.5 is 0.25. So, each part of 4 has a value of 0.25.
1/4 = 0.25
2/4 = 0.50
3/4 = 0.75