1. A sum of money doubles in 20 years on simple interest. It will get triple at the same

1 answer:

5 0

First find the interest rate of the sum of money doubles in 20 years
2p=p (1+rt)
2=1+rt. T=20 years
2=1+20r
Solve for r to get the simple interest rate
2-1=20r
20r=1
R=1÷20
R=0.05

Now find how long will get triple at the same rate
3p=p (1+rt)
3=1+rt. R=0.05
3=1+0.05t
Solve for t
3-1=0.05t
0.05t=2
T=2÷0.05
T=40 years. .....answer

You might be interested in

Which equasion represents a line that is parallel to the line y=-4x+5

Debora [2.8K]

In order to be parallel to your line, a line has to have the same slope as your line. So it has to have slope −4
−
4
.

Thus any line parallel to the line =−4+5
y
=
−
4
x
+
5
has an equation of the form =−4+
y
=
−
4
x
+
b
, where
b
is any number.

4 0

3 years ago

What is 7\15 - 4\9 in fractions

Alex17521 [72]

Answer:

its 7/9

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

Help evaluating the indefinite integral

Dafna11 [192]

Answer:

$\displaystyle \int {\frac{x}{\sqrt{4 - x^2}}} \, dx = \boxed{ -\sqrt{4 - x^2} + C }$

General Formulas and Concepts:
Calculus

Differentiation

Derivatives
Derivative Notation

Derivative Property [Multiplied Constant]:
$\displaystyle (cu)' = cu'$

Derivative Property [Addition/Subtraction]:
$\displaystyle (u + v)' = u' + v'$
Derivative Rule [Basic Power Rule]:

f(x) = cxⁿ
f’(x) = c·nxⁿ⁻¹

Integration

Integrals

Integration Rule [Reverse Power Rule]:
$\displaystyle \int {x^n} \, dx = \frac{x^{n + 1}}{n + 1} + C$

Integration Property [Multiplied Constant]:
$\displaystyle \int {cf(x)} \, dx = c \int {f(x)} \, dx$

Integration Methods: U-Substitution and U-Solve

Step-by-step explanation:

Step 1: Define

Identify given.

$\displaystyle \int {\frac{x}{\sqrt{4 - x^2}}} \, dx$

Step 2: Integrate Pt. 1

Identify variables for u-substitution/u-solve.

Set u:
$\displaystyle u = 4 - x^2$
[u] Differentiate [Derivative Rules and Properties]:
$\displaystyle du = -2x \ dx$
[du] Rewrite [U-Solve]:
$\displaystyle dx = \frac{-1}{2x} \ du$

Step 3: Integrate Pt. 2

[Integral] Apply U-Solve:
$\displaystyle \int {\frac{x}{\sqrt{4 - x^2}}} \, dx = \int {\frac{-x}{2x\sqrt{u}}} \, du$
[Integrand] Simplify:
$\displaystyle \int {\frac{x}{\sqrt{4 - x^2}}} \, dx = \int {\frac{-1}{2\sqrt{u}}} \, du$
[Integral] Rewrite [Integration Property - Multiplied Constant]:
$\displaystyle \int {\frac{x}{\sqrt{4 - x^2}}} \, dx = \frac{-1}{2} \int {\frac{1}{\sqrt{u}}} \, du$
[Integral] Apply Integration Rule [Reverse Power Rule]:
$\displaystyle \int {\frac{x}{\sqrt{4 - x^2}}} \, dx = -\sqrt{u} + C$
[u] Back-substitute:
$\displaystyle \int {\frac{x}{\sqrt{4 - x^2}}} \, dx = \boxed{ -\sqrt{4 - x^2} + C }$