Dominic buys a gallon of milk for $2.29 and a box of cereal for $2.99. He uses a $0.25 coupon and a $0.70 coupon. What is the total cost of Dominic's purchase? Write an expression to show your work.

$4.33

Step-by-step explanation:

Cost of milk + cereal = $2.29 + $2.99 = $5.28

$5.28 - coupons

$5.28 - $0.70 - $0.25 = $4.33

x + 107

step-by-step explanation:

let's say that the number he had before the mistake was x. then, he will have 107 dollars more than this, so the answer is x + 107.

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places