Deepak spent $178 on groceries last
month. if he reduces his grocery costs
by 15% the next month, how much
will he spend on groceries?
a $204.70
b $151.30
c $124.60
d $26.70

B

Step-by-step explanation:

$178 - (.15 • $178) = $151.30

y=mx+b

step-by-step explanation:

m slope, b y-intercept

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