4. Passes through points (6,1) and (-2,5)

y = -1/2x + 4

Step-by-step explanation:

y2 - y1 / x2 - x1

5 - 1 / -2 - 6

4 / -8

= -1/2

y = -1/2x + b

5 = -1/2(-2) + b

5 = 1 + b

4 = b

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