Answer:

Step-by-step explanation:
Let
y --->Mala's age
x---> sister's age
we know that
---> equation A
so
The sum of ages of the sisters is

substitute equation A in the expression of the sum of ages

simplify

C because it's on the next one
I do believe it is a 60 degree angle my friend
Hey!
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The opposite of -10 is 10.
Number line in image below.
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Hope This Helped! Good Luck!
Answer:
Plumber A makes $20 more
Step-by-step explanation:
Plumber A makes $290 in 3 hours (200 + 30 x 3)
Plumber B makes $270 in 3 hours (150 + 40 x 3)
290 - 270 = $20