I am confused please can you help me
1 answer:
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Answer:
The amount invested at 3% is 300 &
The amount invested at 2% is 100.
Step-by-step explanation:
Total yearly interest for the two accounts is: $11
Let x be the amount invested at 3%
& y be the amount invested at 2%
From the question we can get 2 equations as;
x = 3y --------------------------Equation 1
0.03x + 0.02y = 11 ----------Equation 2
Substitute for x in Equation 2 we get;
0.03 (3y) + 0.02y = 11
0.09y + 0.02y = 11
0.11y = 11
Divide the above equation by 0.11, we get;
y =
y = 100
Let us substitute the value of y in Equation 1 we get;
x = 3(100)
x = 300
Now to check our answer let us put in the simple interest formula. If we get the sum of the two interests equal to 11 then our answers are correct:
0.03 x 300 + 0.02 x 100
= 9 + 2
= 11
Hence the amount invested at 3% is 300 and the amount invested at 2% is 100.
Answer:
<em>Thus, the dimensions of the metal plate are 10 dm and 8 dm.</em>
Step-by-step explanation:
For a quadratic equation:
The sum of the roots is -b and the product is c. Note the leading coefficient is 1.
We know the perimeter of the rectangular metal plate is 36 dm and its area is 80 dm^2. Being L and W its dimensions, then:
P=2(L+W)=36
A=L.W=80
Note both formulas are closely related to the roots of the quadratic equation, we only need to adjust the data for the perimeter to be exactly the sum of L+W and not double of it.
Thus we use the semi perimeter instead as P/2=L+W=18
The quadratic equation is, then:
Factoring by finding two numbers that add up to 18 and have a product of 80:
The solutions to the equation are:
x=10, x=8
Thus, the dimensions of the metal plate are 10 dm and 8 dm.