Solve the system of equations by using substitution. 6r + 7s = –1

2r + 4s = –12

1) (–4, –8)

2) (–8, –4)

3) (–7, 8)

4) (8, –7)

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

13. jbhgfsfyfvhvbjko

isn't it a pentagon? sense [3 (triangle) + 4 (rectangle)] - 2 (triangle and rectangle connected) = 5 (pentagon)