21. Shiloh estimated V190 by placing the point on the number line below. Explain how his estimate
could be improved.
13
14

cbnygjdyj

step-by-step explanation:

starting with:    

5 + x - 12 = 2x - 7   

5 + x - 12 - x = 2x - 7 - x (subtract x from both sides)   

5 - 12 = x - 7 (combine and cancel x's from both sides)   

5 - 12 + 7 = x - 7 + 7 (add 7 to both sides)   

0 = x (add numbers together on both sides)       

so in order for the equation to be true, x must be 0.   

trying x = -0.5   

5 + x - 12 = 2x - 7 (original equation)   

5 + -0.5 - 12 = 2(-0.5) - 7 (plug in value of x)   

5 + -0.5 - 12 = -1 - 7 (did multiplication)   

-7.5 = -8 (did addition on both sides)       

since -7.5 is obviously not equal to -8, the value of -0.5 for x is wrong.   

trying x = 0   

5 + x - 12 = 2x - 7 (original equation)   

5 + 0 - 12 = 2(0) - 7 (plug in value of x)   

5 + 0 - 12 = 0 - 7 (did multiplication)   

-7 = -7 (did addition on both sides)       

since -7 equals -7, that demonstrates that the value of 0 for x is correct.   

trying x = 1   

5 + x - 12 = 2x - 7 (original equation)   

5 + 1 - 12 = 2(1) - 7 (plug in value of x)   

5 + 1 - 12 = 2 - 7 (did multiplication)   

-6 = -5 (did addition on both sides)       

since -6 is obviously not equal to -5, the value of 1 for x is wrong.

i think the answer is true

step-by-step explanation:

the answer is $4.45. i started by figuring out the cost of the plates and napkins. the easiest way to figure this cost out is through the tax. we know the way they found the tax is by multiplying the cost of non-food items by the tax rate (5% or 0.5). so, all we have to do to find the cost before tax is set up an equation and work this formula backwards. the equation is 0.19=0.05x where x is the cost of the plates and napkins. now all you do is divide both sides by 0.05 to come up with 3.8=x. now that we know the cost of the plates and napkins is $3.80, all we have to do is subtract this cost from the total cost of $8.25 giving us the cost of the watermelon which is $4.45.