I'm going to use the substitution method.
If y = - 3/2 - 7, then:
1/2x + 5 = - 3/2x - 7
Combine like terms:
4/2x = - 12. Mutiply both sides by 2/4 to get x = -12 (2/4)
Simplify to get:
x = - 6.
Plug - 6 back in for x in either equation.
Y = 1/2( - 6) + 5 which becomes Y = - 3 + 5.
X = - 6, Y = 2
Answer:
Hi! I believe this is your answer:
$750
Step by step explanation:
interest + interest = total interest
0.08*x + 0.09*(9000-x) = 750 dollars
0.08x + 810 - 0.09x = 750
-0.01x = 750 - 810 = -60 ====> x = %28-60%29%2F%28-0.01%29 = 6000.
Final answer:
$6000 was invested at 8%. The rest 9000-6000 = 3000 dollars were invested at 9%.
Check. 0.08*6000 + 0.09*3000 = 480 + 270 = 750 dollars.
<h2>9.</h2><h3>Given</h3>
<h3>Find</h3>
- linear approximation to the volume when the radius increases 0.4 cm
<h3>Solution</h3>
The equation for volume of a sphere is
... V = (4/3)π·r³
Differentiating gives
... dV = 4π·r²·dr
Filling in the given numbers gives
... change in volume ≈ 4π·(15 cm)²·(0.4 cm)
... = 360π cm³ ≈ 1130.97 cm³ . . . . . . volume of layer 4mm thick
<h2>11.</h2><h3>Given</h3>
- an x by x by 2x cuboid with surface area 129.6 cm²
- rate of change of x is 0.01 cm/s
<h3>Find</h3>
<h3>Solution</h3>
The area is that of two cubes of dimension x joined together. The area of each such cube is 6x², but the two joined faces don't count in the external surface area. Thus the area of the cuboid is 10x².
The volume of the cuboid is that of two cubes joined, so is 2x³. Then the rate of change of volume is
... dV/dt = (d/dt)(2x³) = 6x²·dx/dt
We know x² = A/10, where A is the area of the cuboid, so the rate of change of volume is ...
... dV/dt = (6/10)A·dx/dt = 0.6·(129.6 cm²)(0.01 cm/s)
... dV/dt = 0.7776 cm³/s
Answer:
-48
Step-by-step explanation:
12 x 2=24
12 x 6= 72
24 - 72 = -48
Answer:
Fraction form- 2/5
Decimal form- 0.4
Step-by-step explanation:
Distribute.
Have a good day!
