66 bats were sold. some were sold for $42 each the rest were sold for $30 each. the total sales were$2,460. write and solve a system of equations to find out how many bats were sold for $42 each?

40 bats sold for $42

26 bats sold for $30

Step-by-step explanation:

x + y = 66

42x + 30y = 2460

solve first equation for y and plug in for y in second equation

42x + 30 (66 - x) = 2460

x = 40

y = 66- 40 = 26

answer: c

(2, -4)

goes 7 to the

(9, 4)

easy

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: