Answer:
(x=0, y=11)
(x=2, y=9)
Step-by-step explanation:
first equation substitution for x first.
y=11-x
plug into 2nd equation
(x+2)^2+(11-x-7)^2=20
this should lead you into a quadratics equation.
you get x=0, x=2.
do the same for y value this time, subbing in the x value
(11-y+2)^2+(y-7)^2=20
this also leads into a quad equation
solve and you get y=11, and y=9
<span>2 miles in 1212 hour, 1 mile = 1212/2 = 606 hours
so in 3 miles = 606 * 3 = 1,818 hours
answer: 3</span><span> miles in 1818 hours.</span>
X=-2 and y=3.
The first step we take is to substitute the value for y from the second equation into the first equation:
4x+5(3x+9)=7
This is justified by substitution. The next step is:
4x+5*3x+5*9=7
4x+15x+45=7
This is justified by the distributive property. The next step is:
19x+45=7
This is justified by addition of like terms. The next step is:
19x+45-45=7-45
19x=-38
This is justified by the subtraction property of equality. The next step is:
19x/19 = -38/19
x=-2
This is justified by the division property of equality. The next step is:
y=3(-2)+9
y=-6+9
y=3
This is justified by substitution, multiplication and addition, in that order.
Answer:
Step-by-step explanation:
total money = $2.25 = 225 cents
types of denomination in coins or cents are dimes and nickels
dime = 10 cents , nickel = 5 cents
twice of dimes to nickels
let no of dimes = x and no of nickels = y
our equation
10x + 5y = 225
x = 2y
10(2y) + 5y = 225
20y +5y = 225
25 y = 225
y=9
x =2y 2x9 = 18
so the number of dimes = 18 and nickels = 9
cross verification:
10x18 + 5x9 = 180 +45 = 225