Find an equation of the line passing through the point (−3,−7) that is perpendicular to the line y= −5x+4

y = 1/5x - 6.4

Step-by-step explanation:

Perpendicular lines have opposite reciprocal slopes, so the slope will be 1/5

Then, plug the slope and the point into the equation y = mx + b to find b

y = mx + b

-7 = 1/5(-3) + b

-7 = -0.6 + b

-6.4 = b

Then, plug this and the slope into the equation

y = 1/5x - 6.4 will be the equation

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