7. Chris and Elizabeth buy a new car. Elizabeth put 3% of her annual salary towards the first payment, and Chris put 2% of his annual salary. If the total payment was $500, and Chris
makes $2000 a year more then Elizabeth, what is Elizabeth's annual income?
a. $ 8,800
c. $ 9,200
b. $ 11,200
d. $ 10,200

sites:

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204

a. 12.5 kg

step-by-step explanation:

f = ma

so

m = f/a = (2500 n)/(200 m/s²) = 12.5 kg

1 n = 1 kg·m/s²

answer: 0.64

step-by-step explanation: