Answer:
Let's solve your system of equations by elimination.
8x+9y=48;12x+5y=21
Steps:
Multiply the first equation by 5,and multiply the second equation by -9.
5(8x+9y=48)
−9(12x+5y=21)
Becomes:
40x+45y=240
−108x−45y=−189
Add these equations to eliminate y:
−68x=51
Then solve−68x=51for x:
−68x
/−68
=
51
/−68 (Divide both sides by -68)
x= −3
/4
Now that we've found x let's plug it back in to solve for y.
Write down an original equation:
8x+9y=48
Substitute
−3
/4
8x+9y=48:
8(
−3
/4
)+9y=48
9y−6=48 (Simplify both sides of the equation)
9y−6+6=48+6 (Add 6 to both sides)
9y=54
9y
/9 = 54
/9 (Divide both sides by 9) y=6
<em><u>Answer: x= −3
/4 and y=6</u></em>
Hope This Helps! Have A Nice Day!!
Answer:
See Explanation
Step-by-step explanation:
(a) Proof: Product of two rational numbers
Using direct proofs.
Let the two rational numbers be A and B.
Such that:


The product:




Proved, because 1/3 is rational
(b) Proof: Quotient of a rational number and a non-zero rational number
Using direct proofs.
Let the two rational numbers be A and B.
Such that:


The quotient:

Express as product



Proved, because 3/4 is rational
(c) x + y is rational (missing from the question)
Using direct proofs.
Let x and y be
Such that:


The sum:

Take LCM


Proved, because 7/6 is rational
<em>The above proof works for all values of A, B, x and y; as long as they are rational values</em>
Answer:
- (x -3)(x+3)(2x +1)
- (x -1)(x +1)(x +3)
- (2x -1)(2x +1)(x -4)
Step-by-step explanation:
A) 2x³ +x² -18x -9 = x²(2x +1) -9(2x +1) = (x² -9)(2x +1) = (x -3)(x+3)(2x +1)
__
B) x³ +3x² -x -3 = x²(x +3) -1(x +3) = (x² -1)(x +3) = (x -1)(x +1)(x +3)
__
C) 4x³ -16x² -x +4 = 4x²(x -4) -1(x -4) = (4x² -1)(x -4) = (2x -1)(2x +1)(x -4)
_____
In each case, the third-level factoring mentioned in step 4 is the factoring of the difference of squares: a² -b² = (a -b)(a +b).
_____
The step-by-step is exactly what you need to do. It is simply a matter of following those instructions. You do have to be able to recognize the common factors of a pair of terms. That will be the GCF of the numbers and the least powers of the common variables.
Answer:
A
Step-by-step explanation:
to solve absolute value inequalities you must solve it for when the absolute value is positive and then when it is negative
example, |4| = 4 and -4
first solution will be when we're solving for the positive value:
+(-4x+7) ≥ 27
-4x + 7 ≥ 27
-4x ≥ 20
x ≤ -5 [reverse the symbol when mult or div by a negative]
-(-4x+7) ≥ 27
4x - 7 ≥ 27
4x ≥ 34
x ≥ 34/4 or x ≥ 8 1/2
solution: x ≤ -5 or x ≥ 8.5