Answer:
Step-by-step explanation:
<u>Given expressions:</u>
- 8 = x - 2 ⇒ x = 8 + 2= 10
- 3 = x ÷ 4 ⇒ x = 3*4 = 12
- x - 6 = 5 ⇒ x = 5 + 6 = 11
- x - 3 = 9 ⇒ x = 9 + 3 = 12
3 of them involves addition, one of them - multiplication
The second expression doesn't belong
A) 2x -3(3x -7) = 7 . . . . substitute for y
.. -7x = -14 . . . . . . . . . . . subtract 21
.. x = 2 . . . . . . . . . . . . . divide by -7
.. y = 3*2 -7 = -1 . . . . . . substitute for x
(x, y) = (2, -1)
B) 5(5x -2y) -2(3x -5y) = 5(8) -2(1) . . . . subtract 2 times 2nd equation from 5 times 1st
.. 19x = 38 . . . . simplify
.. x = 2 . . . . . . . divide by 19
.. y = (5x -8)/2 = 1 . . . . solve 1st equation for y, substitute x
(x, y) = (2, 1)
C) See the first graph.
(x, y) = (-4, 1)
D) See the second graph.
(x, y) = (3, 2)
Answer: INDEiAaaaaaaaaaaaaaaa
Answer:
(7/15,−13/5)
Equation Form:
x=7/15,y=−13/5
Step-by-step explanation:
Solve for the first variable in one of the equations, then substitute the result into the other equation.
Answer: 0.87400mg of caffeine.
Step-by-step explanation:
You have
N(t)=N0(e^−rt)(1)
as a general Exponential decay equation where N0 is the amount at t=0, N(t) is the amount remaining at time t and r is the exponential decay constant. You're specifically given that after 10 hours, the decay factor is 0.2601, i.e.,
N(10)/N(0)=N0(e^−10r)/N0(e^0)= e^−10r=0.2601 . .(2)
Taking the last 2 parts of (2) to the power of 0.1t gives
e^−rt=0.2601^.1t . .(3)
This means that
N(t)=N0(e^−rt)=N0(0.2601^.1t). .(4)
Also,
N(2.56)N(1.56)=N0(0.2601.1(2.56))N0(0.2601.1(1.56))=0.2601.1(2.56−1.56)=0.2601^.1
= 0.87400mg of caffeine.