Answer:
(
+
1
)
(
+
9
)
Step-by-step explanation:
I don’t know what is your problem is
So... the radiator has 15 liters of 70% antifreeze.. but needs an 80% antifreeze
well, so, you need to drain some and put some with higher percentage, seems to be, you will end up at the same 15 liters, possible the radiator's capacity, of 80% antifreeze
so, the same amount going out, of 70% is the same amount going in, of 100% antifreeze
now.. let's use the decimal format for the percents, or 70% is 70/100 or 0.7 and so on

so.. let's subtract, from the current solution, 0.7x and add 1x or x, our antifreeze concentration amount, should be 12 though
10.5 - 0.7x + x = 12
solve for "x"
Answer:
Step-by-step explanation:
A. distribute the X to the X in the parenthesis and you get 2x. Then distribute the X to the -7 in the parenthesis and you get -7x. Combine like terms so that would be 2x-7x and you get -5x.
C. distribute the 6x to the X in the parenthesis and you get 7x. Then distribute the 6x to the 2 in parenthesis and you get 8x. Combine like terms so that would be 7x+8x and you get 15x.
E. Not sure on this one, sorry.
The answer is 10 hope it helps SORRY IF I’M WRONG