The sum of a number y and 9 is at least -1 ?

(y + 9) ≥ -1

Step-by-step explanation:

Step 1:  Convert words into an expression

The sum of a number y and 9 is at least -1

(y + 9) ≥ -1

 (y + 9) ≥ -1

If needed solve

y + 9 - 9 ≥ -1 - 9

y ≥ -10

77

step-by-step explanation:

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