Add all the numbers together, and divide your total by the number of value there (in this case, 7). The nearest tenth is to one place after the decimal.
You can seperate it into two triangles then take the area of each of those (a=1/2bh) and add each triangles area together
We have a pair of vertical angles here. So they would equal each other.
3x+50=6x-10
Subtract 3x to 6x:
50=3x-10
Add 10 to 50:
60=3x
Divide 3 to both sides:
x=30
Answer: girls=20, sister=10
Step-by-step explanation:
Let x = the girl's sister's age (present)
Let 2x= the girl's age (present)
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According to the question
(x+5)(2x+5)=375
Expand parentheses by FOIL (First Outer Inner Last)
2x²+5x+10x+25=375
Combine like term (5x and 10x)
2x²+15x+25=375
Subtract 375 on both sides
2x²+15x+25-375=375-375
2x²+15x-350=0
Find the factors (cross factor)
(x-10)(x+17.5)=0
x=10 or x=-17.5 (rej) ⇔ the age can't be negative
the girl's age is 20, and her sister's age is 10.
