Write the ratio 21/25 as a percent
2 answers:
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Answer:
x=1, y=7
Step-by-step explanation:
y = -3x + 10 - first equation
y=-3x + 4 - second equation
rearrange the expression to
-3x-y= -10
3x-y= -4
pick an equation and simplify; lets pick the second equation
3x-y= -4
divide 3 by both sides
x= - third equation
substitute the value of x into an equation; lets pick the first equation
-3x-y= -10
-3- y = -10
simplify. -3 cancels 3 so we are left with
-1(-4+y)-y = -10
simplify
4-y-y= -10
4-2y= -10
subtract 4 from both sides
-2y= -10-4
-2y= -14
divide -2 by both sides
y=7
substitute the value of y, (y=7) in an equation, we are using the second equation
3x-y= -4
3x-7= -4
3x = -4+7
3x= 3
divide 3 by both sides
x=1
so the answer is x=1, y=7
Answer:
a. 720
b. 0.3
Step-by-step explanation:
a.
Three balls are selected at random without replacement.
First ball can be selected in 10 ways
Second ball can be selected in 9 ways
Third ball can be selected in 8 ways
Thus, there are 10×9×8 =720 different ways of selecting three balls.
b.
There are three cases that satisfy this condition
- first ball picked is 5, the others are not
- first ball is not 5, second is 5, third is not
- first and second ball is not five, third ball is 5
Each probabilities are:
Thus, one of the balls selected is the number 5 is then
Answer:
See attached for a "Neat" quadratic formula.
a = -1
b = 2
c = 1
x = [-2 +- sqr root( 4 -4*-1*1)] / -2
x = [-2 +- sqr root( 4 -4*-1*1)] / -2
x = [-2 +- sqr root(8)] / -2
x1 = (-2 +2.8284271247) / -2
x1 = .8284271247 / -2
x1 = -0.41421
x2 = (-2 -2.8284271247) / -2
x2 = ( -4.8284271247) / -2
x2 = 2.4142135624
So the equation has the positive solution of
2.4142135624
Step-by-step explanation:
