What are the soultion(s) to the quadratic equation 40- x^2=0

Step-by-step explanation:

40 - x^2 = 0...subtract 40

-x^2 = -40multiply both sides by -1

x^2 = 40

x = (+ - ) sqrt 40

x = (+ - ) sqrt 4 * 10

x = (+ - ) 2 sqrt 10

x = 2 sqrt 10, and x = -2 sqrt 10

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.