Can someone me with this problem? you need to find the value of x and y by using the strategy of elimination. show your work.
here are the two equations:
7x + 8y = 20
7x - 2y = 29

in advance!

x = 136/35; y = -⁹/₁₀

Step-by-step explanation:

(1)         7x + 8y = 20

(2)        7x – 2y = 29       Subtract (2) from (1)

                  10y =  -9        Divide each side by 10

(3)                 y =  -⁹/₁₀     Substitute (3) into (1)

      7x - 2(-⁹/₁₀) = 29

      7x + 18/10  = 29                       Subtract 18/10 from each side

      7x              =      29 - 18/10

      7x              = (290 - 18)/10

      7x              =          272/10        Divide each side by 7

        x              =           272/70

        x              =           136/35

x = 136/35; y = -⁹/₁₀

Check:

(1) 7(136/35) + 8(-⁹/₁₀) = 20

      136/5    -   72/10 = 20

      136/5    -   36/5  = 20

                      100/5  = 20

                       20      = 20

(2) 7(136/35) – 2(-⁹/₁₀)  = 29

       136/5    +    18/10 = 29

       136/5    +      ⁹/₅    = 29

                        145/5  = 29

                        29       = 29

i really dont know

step-by-step explanation:

d. millimeters per hour.

step-by-step explanation:

we are given that,

carlo used a rain gauge to measure the amount of water his lawn is receiving from the sprinklers.

since, according to the options, we see that,

water cannot be measured by 'miles per hour', 'meters per second' and 'grams per seconds'.

we get that, the water can be measured by 'millimeters per hour'.

hence, the appropriate rate for describing the amount of water is 'millimeters per hour'.