When the solution of x2 + 9x − 9 is expressed as negative 9 plus or minus the square root of r, all over 2, what is the value of r? x equals negative b plus or minus the square root of b squared minus 4 times a times c, all over 2 times a 117 54 45 9

it would open into a square depending on the type of envelope i’m not sure about the second part

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:

y/x of point b= y/x of point a

step-by-step explanation:

(i got the same question, this was the correct answer.)

step-by-step explanation:

a'(12.5,11.25)

slope=(y1-y2)/(x1-x2)