Answer:
D
Step-by-step explanation:
r = 5 units
The amount that Edgar borrowed from the bank is $5,000. From his mom is $2,600 while from his friend is $2,400. This can be checked using the total interest of $624.
Bank: $5,000 x 0.07 = $350
Mom: $2,600 x 0.05 = $130
Friend: $2,400 x 0.06 = $144
Adding all three results to $624.
Step-by-step explanation:
Mei runs 6 days each week.
=> Mei runs 18 days in 3 weeks.
Since she ran 92.16 miles in 18 days,
She ran 92.16 miles / 18 days
= 5.12 miles/day.
( 356 x 280 ) - ( 103 x 60 )
99 680 - 6180 = 93500
answer = 93500
x - 2y + z = 5 | *2
⇒ 2x - 4y+ 2z=10
3x + 3y - 2z = - 6 } I sum up these relations
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2x+3x - 4y+3y+2z-2z=10-6
5x - y = 4 (1)
3x + 3y - 2z = - 6 | *3 ⇒ 9x + 9y - 6z = - 18
2x - y + 3z = 11 | *2 ⇒ 4x - 2y + 6z= 22 I sum up these
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⇒ 9x+4x+9y-2y-6z+6z= 4
13x+ 7y= 4 (2)
I write (1) and (2)
5x - y = 4 | *7
35x - 7y= 28
13x+7y=4
48x = 32
x= 32/48=4/6 ( 32:8=4, 48:8=6)
x= 2/3
5x-y=4,
5*2/3-y=4
y=10/3 -4=10/3-12/3=-2/3
⇒ y= - 2/3
x - 2y + z = 5
2/3 - 2*(-2/3)+z=5
2/3+4/3+z=5
6/3+z=5
2+z=5
z=3
x+y+z=2/3-2/3+3=3
x+y+z=3
