4) a: 6x − 3y = −4 b: −4x − y = 5 to solve this system of equations by elimination, what could you multiply each equation by to cancel out the y-variable? a) multiply a by 2 and b by 3 b) multiply a by 1 and b by −3 c) multiply a by 3 and b by 2 d) multiply a by 1 and b by −2

It’s B

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