Let
R = Ralph's age
S = Sara's age
First statement is translated as:
S = 3R
Second statement is translated as:
S + 4 = 2(R + 4)
Use the first equation to be substituted into the second one in terms of R which is the one we are actually going to solve for Ralph's age.
Since S = 3R, then
3R + 4 = 2(R + 4)
3R + 4 = 2R + 8
3R - 2R = 8 - 4
R = 4 years old
Answer:
12.5%
Step-by-step explanation:
The price increased from 800 to 900. So what is the PERCENTAGE INCREASE??
The increase is 900 - 800 = 100
To find this in terms of original, we need to divide 100 by 800 and multiply by 100 to get the "percentage". Let's do it:

So the increase is 12.5% and thus the general sales tax is 12.5%
Answer:
Step-by-step explanation:
mid point formula = (x1+x2/2 , y1+y2/2)
hence putt the values we get,
mid point = ( -1+3/2 , 7-2/2)
= (1 , 2.5)