Answer:
For f(x) = √(2·x + 2) - √(x + 18), at f(x) = -1 the possible x-values includes;
-0.757, -17.5
Step-by-step explanation:
Given that the function is f(x) = √(2·x + 2) - √(x + 18)
The value of 'x' when f(x) = -1, is given as follows;
-1 = √(2·x + 2) - √(x + 18)
-1² = (√(2·x + 2) - √(x + 18))² = 3·x + 20 - 2·√(2·x + 2)×√(x + 18)
1 = 3·x + 20 - 2·√(2·x + 2)×√(x + 18)
2·√(2·x + 2)×√(x + 18) = 3·x + 20 - 1 = 3·x + 19
2·x² + 38·x + 36 = (3·x + 19)/2
2·x² + 38·x + 36 - (3·x + 19)/2 = 0
4·x² + 73·x + 53 = 0
From which we get;
x = (-73 ± √(73² - 4 × 4 × 53))/(2 × 4)
x ≈ -0.757, and x ≈ -17.5
Answer:
you average the scores by adding scores from exam 1 and exam 2 then divide it by 2 to average the exam scores
Step-by-step explanation:
Solve by elimination.
The goal is to cancel out one of the variables in order to easily solve for the other variable.
Do this by changing the equations so that the coefficients of either x or y add up to 0.
Notice the coefficients of y are 3 and 3, if we make one of them negative then they add up to 0. 3+ (-3) = 0
Multiply 2nd equation by -1.
6x +3y = 9
-2x -3y = -1
__________
4x +0y = 8
Solve for x
4x = 8
x = 8/4 = 2
Plug x=2 back into one of original equations to find y.
---> 2(2) + 3y = 1
---> 4 + 3y = 1
---> 3y = -3
---> y = -1
Therefore solution is (2,-1)
Answer:
x=3 and y=2
Step-by-step explanation:
1.) 4x+3(5x-13)=18
expand into 4x+15x-39=18
18+39= 57
15x+4x= 19x
57/19= 3 so x=3
substitute 3 into y= 5x - 13
and you get 2 so y=2