1: 25(x^2−3)+11=17

2:If using the method of completing the square to solve the quadratic equation x^2-13x+14=0, which number would have to be added to "complete the square"?

3:If using the method of completing the square to solve the quadratic equation x^2-13x+14=0, which number would have to be added to "complete the square"?

4:x^2-6x=7

5:x^2+22=−12x

1.the answer is +9/5 or - 9/5.

4.answer is 7 and - 1

Step-by-step explanation:

1.open the brackets

25x^2-75+11-17=0

25x^2-81=0

25x^2=81

x^2=81/25

x=+9/5

x=-9/5

4.x^2-6x-7=0

Factorise it and you get

(x-7)(x+1)=0

Where x-7 is 0 or x+1 is 0

So x can be 7 and - 1

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