Jeremy sprinted for 123 seconds and rested. Then he sprinted for 157 seconds, rested, and sprinted again for 195 seconds. Estimate the combined time he sprinted by rounding to the nearest ten and then adding the rounded numbers.

step-by-step explanation:

in the absence of parentheses, i will have to make some assumptions:   i interpret your (3x+5/y^6)(4y^3/5)​ to mean:

3x + 5     4y^(3/5)       (3x + 5)(4)

* =

    y^6             1               y^(6-3/5)

if this is not what you expected, repost your question using parentheses to indicate whether you meant

4y^3

    or   4y^(3/5)

    5

4 + 5 7/9= 9 7/9

step-by-step explanation: