8x-9y=19
4x+y=-7
Multiply all terms of the 2nd by (9)===> 36x + 9y= 63
add (36x 9y= 63) to the 1st ===> 44x+0y = -44 ===> x=-1
replace x by this value in any of the equation & you'll get y=-3
16/3 is rational simply because it is a fraction made up of whole numbers.
Irrational numbers cannot be expressed as fractions made up of whole numbers.
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.
Answer:
300 cubic inches
Step-by-step explanation:
The volume of the top triangular prism is 1/2(area of base)(height)
1/2(50)(6)
1/2(300)
150 cubic inches
The volume of the bottom triangular prism is the same as the top, 150 inches., because it has the same measurements.
Add the two volumes together to get 300 cubic inches, which is the volume of the figure.
Answer:
Step-by-step explanation:
Check attachment for solution
