Complementary angles add up to 90 degrees.
So to find A you would need to add A and B together and equal it to 90 (3x+25+5x-7=90)
Combine like terms together (8x+18=90)
Subtract 18 from night sides (8x=72)
Divide by 8 on both sides (x=9)
Then to find A substitute x into its equation (3(9)+25)=(27+25)=52
A=52 I think
He will mix some 20% solution and some 70% solution to make 60% solution.
Let x = number of liters of 20% solution.
Let y = number of liters of 70% solution.
He wants to make 50 liters of 60% solution, so
x + y = 50 First Equation
The amount of acid in x amount of 20% solution is 20% of x, or 0.2x
The amount of acid in y amount of 70% solution is 70% of y, or 0.7y
The amount of acid in 50 liters of 60% solution is 60% of 50 liters, or 0.6 * 50 = 30
Now we add the amounts of acid.
0.2x + 0.7y = 30 Second Equation
x + y = 50
0.2x + 0.7y = 30
-0.2x - 0.2y = -10
0.2x + 0.7y = 30
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0.5y = 20
y = 40
x + y = 50
x + 40 = 50
x = 10
Answer: He needs 10 liters of 20% solution and 40 liters of 70% solution.
Answer:
19.125
Step-by-step explanation:
multiply 15.5 by 3 and then divide the answer by 4
♥It says that he adds 12$ each week, and by the end of 3 weeks he had 60. Well if you do 12*3
And that =36.
But as you can see its not 60 so we have to find out how much money he had in there before.
He had 24$ in there before he started doing this.
You can find this by doing 36+x=60 and 36+24=60.
Now if you do 12*15
You get 180.
Now add the 24 dollars he already had in there.
180+24=204
He had 204$ at the end of wk.15
♥Hope this helps!♥
Answer: 10
Step-by-step explanation:
1. Write the fractions as 2/9 times 45/1.
2. Cross cancel 45 and 9 by dividing by 5, which now gives you 2/1 and 5/1.
3. Multiply 2/1 and 5/1 and you get 10.
I hope this helps!
