5x+7y=25
5x-2y=-65
subtract both of the equations
5x-5x=0
7y--2y= 7y+2y=9y
25--65=25+65=90
0+9y=90
9y=90
divide both sides by 9 to get y by itself
9y/9=90/9
cross out 9 and 9 which becomes 1*1*y=y
90/9=10
y=10
find x by using the substitution method
5x+7y=25
5x+7(10)=25
5x+70=25
move +70 to the other side
sign changes from +70 to -70
5x+70-70=25-70
5x=-45
divide both sides by 5 to get x by itself
5x/5=-45/5
cross out 5 and 5 then becomes 1*1*x=x
-45/5=-9
x=-9
answer:
(-9,10)
Answer:
Yes
Step-by-step explanation:
Because it passes vertical line test.
a < -9
Rearrange:
Rearrange the equation by subtracting what is to the right of the greater than sign from both sides of the inequality :
5*a+18-(-27)<0
Step by step solution :
Step 1 :
Pulling out like terms :
1.1 Pull out like factors :
5a + 45 = 5 • (a + 9)
Equation at the end of step 1 :
Step 2 :
2.1 Divide both sides by 5
Solve Basic Inequality :
2.2 Subtract 9 from both sides
a < -9
Answer:
Step-by-step explanation:
5x3x4= 
Answer:
7/20
Step-by-step explanation:
Seventh grade: Total = 3 + 7 = 10
Number of boys = 7 boys
Probability of a boy being picked = 7/10
Eighth grade: Total 5 + 5 = 10
Number of boys = 5
Probability 5/10 = 1/2
The probability of the correct outcome = 7/10 * 1/2 = 7 / 20
Answer: 7 / 20
