Answer:

Step-by-step explanation:
=> 5x-4+2(x-4) = 16
Expanding the brackets
=> 5x-4+2x-8 = 16
Combining like terms
=> 5x+2x-4-8 = 16
=> 7x - 12 = 16
Adding 12 to both sides
=> 7x = 16+12
=> 7x = 28
Dividing both sides by 7
=> x = 4
Answer:
C
Step-by-step explanation:
A and B are not straight lines, so they are not linear functions.
C and D are straight lines, so they are linear. However, D fails the vertical line test, so it is not a function.
Answer: b
Step-by-step explanation:
In the last question, you wrote on a second equation "13x ...." kkk
Let's go:
We have to check each one answer in the following system:
x - 2y = 7
3x + 7y = 8
I can use the substituition method to solve this system...
x = 7 + 2y
3x + 7y = 8
3(7 + 2y) + 7y = 8
21 + 6y + 7y = 8
13y = 8 - 21
13y = -13
y = -1
x = 7 + 2.(-1)
x = 5
Finally, the correct answer is the second one (letter b).
I belive his answer is wrong B/c the graph does not even start near 310 the first to bars make it to 50 and 150 so even if u add the two together it would only be 200 so, the answer would be B