Answer:
Step-by-step explanation:
6x + 3y = -18
Taking 3 common from left side
so, 3(2x+y) = -18
2x+y = -18/3
2x+y = -6 (equation 1)
and, 7x + 7y = 0
Taking 7 as commom from left side
7(x + y) = 0
x + y = 0/7
x + y = 0 (equation 2)
now , by using elimination method
subtracting equation2 from equation1
2x + y - (x + y)= -6 - 0
2x + y - x - y = -6
x = -6
so, x = -6
substituting value of x in equation 1
2(-6) + y = -6
-12 + y = -6
y = -6 +12
y = 6
hence, the value of x = -6
and value of y = 6
Solve for y in the first equation.
y = 4x + 6
Substitute <span>4x + 6 into the second equation.
-5x - (</span><span>4x + 6) = 21
Distribute
-5x - 4x - 6 = 21
Combine like terms
-9x = 27
Divide both sides by -9
x = -3
Substitute back into first equation
-4(-3) + y = 6
Solve for y
y = -6</span>
The roots are 1 +√7 and 1 -√7.
<h3>What is Quadratic equation?</h3>
A quadratic equation in the variable x is an equation of the form ax² + bx + c= 0, where a, b, c are real numbers, a≠0
Given equation:
y= x²+2x-6
First,
Half the coefficient of x and add and subtract the square of (b/2)
y= x²+2x-6+(1)²-(1)²
y= x²+2x+(1)² -6 -(1)²
y= (x+1)² -7
Now, equate y=0
(x+1)² -7 =0
(x+1)² = 7
x+1= ±√7
x=1 ±√7
Hence, the roots are 1 +√7 and 1 -√7.
Learn more about quadratic equation here:
brainly.com/question/1962219
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Answer:
685.75
Step-by-step explanation:
650*0.055+650
9514 1404 393
Answer:
350 km/h
Step-by-step explanation:
Speed = distance/time
speed = (700 km)/(2 h) = 350 km/h
