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Answer:
The value of k is 4 and q is 16.
Step-by-step explanation:
First, you have to expand the brackets by applying :
Next, you have to do it by comparison :
-5- is the correct answer
Answer:
She is not correct because she did not substitute the same number in both expressions in Step 1
Step-by-step explanation:
CASE 1: substitute 1 for x to both sides of the equations
L.H.S
-(4x-5)+2(x-3)
-(4 (1) - 5)+ 2(1-3) = - (-1) + 2(-2) = 1 - 4 = -3
R.H.S
-2x - 5
-2(1) - 5 = -2-5 = -7
Hence for x= 1
-(4x-5)+2(x-3) ≠ -2x -5
Because -3 ≠ -7
CASE 2: substitute -1 for x to both sides of the equations
L.H.S
-(4x-5)+2(x-3)
-(4 (-1) - 5)+ 2(-1-3) = - (-9) + 2(-4) = 9 - 8 = 1
R.H.S
-2x - 5
-2(-1) - 5 = 2-5 = -3
Hence for x= -1
-(4x-5)+2(x-3) ≠ -2x -5
Because 1 ≠ -3
Answer:
She is not correct because she did not substitute the same number in both expressions in Step 1
Because of the relatively large coefficients {9, 42, 49}, applying the quadratic formula would be a bit messy. Instead, I've chosen to "complete the square:"
9x^2 + 42x + 49 = 0 can be re-written as 9 [ x^2 + (42/9)x ] = -49
Dividing both sides by 9, we get [ x^2 + (42/9)x ] = - 49/9
Completing the square: [ x^2 + (42/9)x + (21/9)^2 - (21/9)^2 ] = -49/9
[ x + 21/9 ]^2 = 441/81 - 441/81 = 0
Then [ x + 21/9 ] = 0, and x = -21/9 (this is a double root).
