Sasha is becoming a stronger runner. Last year she ran five miles in 50 minutes. This year her timing improved by 20%. How long does it take her to run five miles?

40 minutes

Step-by-step explanation:

Last year she ran five miles in 50 minutes

This year her timing improved by 20%. This means she runs 5 miles in 20% less time than last year

How long does it take her to run five miles?

= 50 minutes - 20% of 50 minutes

= 50 minutes - 20/100 * 50 minutes

= 50 minutes - 0.2 * 50 minutes

= 50 minutes - 10 minutes

= 40 minutes

This year, it takes her 40 minutes to run 5 miles

center (1,3) with radius 6

step-by-step explanation:

we must complete the square to find the center and radius of the circle.

first make sure the x and y squared terms have 1 as their coefficients. we also make sure x and y terms together.

we now create space between the x and y terms with parenthesis.

we complete the square by taking the middle terms -2x and the -6y - divide each and square them.

we add the squares to both sides.

simplify.

and write the quadratics in factored form.

the center is (h,k) or (1,3). the radius is the square root of 36 which is 6.

explanation:

infrared radiation has wavelength in the range between 700 nm and 1 mm. lets' convert these values into scientific notation, keeping in mind that:

let's start from the lower value, we have:

(we moved the dot two places to the left, so we increased the exponent by 2 units, from -9 to -7)

the higher value is:

so, the range of wavelength of infrared radiation is: