Answer:
15
Step-by-step explanation:
you have to multiply first because of the order of operations, so 2 × 3 = 6, and 6 + 9 = 15
Answer:
-2.4-(-7) has the same result as -2+7 because the negative sign and the minus sign cancel each other out. Think of it like this. If you cross the negative sign and the minus sign together, then it makes a plus sign.
Step-by-step explanation:
I gave a basic answer. You might have to elaborate more on this.
Answer:
We have 40% antifreeze and 70% antifreeze and we need to make 240 liters of 64% antifreeze.
We set up 2 equations where "f" is the 40 % and "s" is the 70%
A) f + s = 240
B) .40f + .70s = (.64 * 240) (or 153.6)
To solve both equations we multiply A) by -.40
A) -.40 f - .40 s = -96.00 then we add this to B)
B) .40f + .70s = 153.60
.30s = 57.6
s = 192
f = 48
48 liters of 40% = 19.20 liters of antifreeze
192 liters of 70% = 134.40 liters of antifreeze
That equals 153.60 liters of antifreeze in a TOTAL liquid amount of 240 liters.
Double Check
153.60 / 240 = 64% antifreeze.
Step-by-step explanation: