(2x-5y)+(x+y)=(2x+x)+(-5y+y)=3x-4y.
therefore:
(2x-5y)+(x+y)=3x-4y
X²-4x+(4/2)²-(4/2)²+13=0
x²-4x+4-4+13=0
-4 should be added
Mark brainliest please
Answer:
1..25a
Step-by-step explanation:
a + 25%·a = a(1 + 0.25) = 1.25a
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<em>Comment on percentages</em>
The symbol "%" is a shorthand way to write "/100", so 25% = 25/100 = 0.25.
Of course, 100/100 = 100% = 1.
Adding 25% of something to 100% of it gives 125% of it, the original amount multiplied by 125/100 = 1.25.
Got a calculator? all you do for #1 and #2 is multiply the two numbers and that is the value for x.
These problems are cross multiplication.
For the next two:
.25x = 6
divide both sides by .25
x = 24
NEXT ONE:
.49x = 12
divide both sides by .49
x = 24.48