Let x be the amount he invests at 6%
1280 = 0.06x + 0.07(20000 - x)
1280 = 0.06x + 1400 - 0.07x
1280 - 1400 = -0.01x
-120 / -0.01 = x
x = 12000
Therefore, he invests $12,000 at 6% and $8,000 at 7%
Answer:
he bought 60 stamps
Step-by-step explanation:
6*5=30
30*2=60
Answer:
x=a(m/q)
a= x(q/m)
Step-by-step explanation:
we just has to invert the function to take expression to the other side of equality.
hope so you will understand.
X+y=17 solve for a variable and plug into the 2nd equation
(x+3)/y=1 also could be written as x+3=y
x=17-y
17-y+3=y combine and add y over to other side
20=2y
y=10
plug back in x+10=17
x=7
so the original fraction is 7/10
Answer:
100 is the correct answer.
Step-by-step explanation:
=2×2×5×5
=4×25
=100
Hope this helps you. Have a nice day. Please mark as brainliest. It helps a lot. :)
