Answer:
x = 8
y = -7
Step-by-step explanation:
This is a system of equations called simultaneous equations. We shall solve it by elimination method Step 1We shall label the equations (1) and (2)−3y−4x=−11.....(1)3y−5x=−61......(2)Step 2Multiply each term in equation (1) by 1 to give equation (3)1(-3y-4x=-11).....(1)-3y-4x=-11....(3)Step 3Multiply each term in equation 2 by -1 to give equation (4)-1(3y−5x=−61)......(2)-3y+5x=61.....(4)Step 4-3y-4x=-11....(3)-3y+5x=61.....(4)Subtract each term in equation (3) from each term in equation (4)-3y-(-3y)+5x-(-4x)=61-(-11)-3y+3y+5x+4x=61+110+9x=729x=72Step 5Divide both sides of the equation by 9, the coefficient of the unknown variable x to find the value of x 9x/9 = 72/9x = 8Step 6Put in x = 8 into equation (2)3y−5x=−61......(2)3y-5(8)=-613y-40=-61Collect like terms by adding 40 to both sides of the equation 3y-40+40=-61+403y=-21Divide both sides by 3, the coefficient of y to find the value of y 3y/3=-21/3y=-7Therefore, the values of x and y that satisfy the equations are 8 and -7 respectively
Answer:
area = 21 feet^2
Step-by-step explanation:
Area of a triangle is 1/2(base*height)
1/2(6*7) = area
1/2(42) = area
area = 21 feet^2
Option D. 2(n + 9) is the right answer
Step-by-step explanation:
The word problems are converted into mathematical problems to solve simply.
for the given problem
"two times the sum of a number and 9"
Let n be a number then
when there is and between two things they are performed first then next operation is performed so
the sum of a number and 9
Then
two times the sum of a number and 9
Hence,
Option D. 2(n + 9) is the right answer
Keywords: Mathematical notation
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