The solution of the equation x2+7x is 0, -7 using the quadratic formula.
Step-by-step explanation:
x2 + 7x = 0
-b ± √
b2 - 4(ac)/ 2a
substitution,
a = 1, b = 7, c = 0
= -7 ± √(7)2 - 4(1 x 0) / 2 x 1
= - 7
± 7 / 2
x = 0 , -7
Answer:
(-3, -6)
explanation:
When reflected across x axis, the x value will be same and y value will become negative.
original coordinates of D: (-3, 6)
- so new coordinates: (-3, (-)6) = (-3, -6)
Answer:
X=3
Y=1
Step-by-step explanation:
In solving simultaneous equations, there are three methods, we have the elimination method, substitution method or graphical method. But for the purpose of this question, we would be using Elimination method.
5y-4x =-7 Equation 1
2y+4x=14 Equation 2
Since x has the same coefficient, it's easy to eliminate by adding up the two equations
5y+2y=7y
-4x+(+4x)=0
-7+(+14)=7
We have 7y=7
Divide both sides by 7,
y=7/7
y=1
Substituting for y in equation 2.
2(1)+4x=14
2+4x=14
4x=14-2
4x=12
x=12/4
x= 3
Answer:
2. x = 2 & y = 4
3. x = 4 & y = 2
Step-by-step explanation:
2. x + y = 6
2x + y = 8 (multiply the first equation by -1, so you can eliminate the ys)
- x - y = -6
2x + y = 8 (now add the variables together)
x = 2 (plug in x in one of the equations to find out y)
x + y = 6
(2) + y = 6
-2 -2
y = 4
3. 3x + y = 14
x = 2y (plug in x into the first equation and solve it for y)
3(2y) + y = 14
6y + y = 14
7y = 14
y = 2 (plug in y in one of the equations to find out x)
x = 2y
x = 2(2)
x = 4
4. One number (x) is 2 more (+2) than twice (times 2) as large as another. their sum is 17. Find the numbers.
2x + 2 = 17 (solve for x)
-2 -2
2x = 15
x = 7.5
6. 7 (4x + 1) - (x + 6) (start by distributing 7 into the first parenthesis)
(28x + 7) - (x + 6) (do the same to the other parenthesis by distributing -1)
(28x + 7) (-x - 6) (and now just combine like terms)
28x + 7 - x - 6
28x - x + 7 - 6
27x + 1
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