Answer:
$3000
$1000
Step-by-step explanation:
the formula for simple interest = principal x time x interest rate
let the amount invested in the 2% investment be a
let the amount invested in the 3% investment be (4000 - a)
(a x 0.02 x 1) + ([4000 - a] x 0.03 x 1) = $90
0.02a + 120 - 0.03a = 90
Collect like terms and solve for a
0.01a = 30
a = $3000
The amount invested in the 3% investment be (4000 - a) = $4000 - $3000 = $1000
<span>sqrt(3x+7)=x-1 </span>One solution was found : <span> x = 6
</span>Radical Equation entered :
<span> √3x+7 = x-1
</span>
Step by step solution :<span>Step 1 :</span>Isolate the square root on the left hand side :
Radical already isolated
<span> √3x+7 = x-1
</span>
<span>Step 2 :</span>Eliminate the radical on the left hand side :
Raise both sides to the second power
<span> (√3x+7)2 = (x-1)2
</span> After squaring
<span> 3x+7 = x2-2x+1
</span>
<span>Step 3 :</span>Solve the quadratic equation :
Rearranged equation
<span> x2 - 5x -6 = 0
</span>
This equation has two rational roots:
<span> {x1, x2}={6, -1}
</span>
<span>Step 4 :</span>Check that the first solution is correct :
Original equation
<span> √3x+7 = x-1
</span> Plug in 6 for x
<span> √3•(6)+7 = (6)-1
</span> Simplify
<span> √25 = 5
</span> Solution checks !!
Solution is:
<span> x = 6
</span>
<span>Step 5 :</span>Check that the second solution is correct :
Original equation
<span> √3x+7 = x-1
</span> Plug in -1 for x
<span> √3•(-1)+7 = (-1)-1
</span> Simplify
<span> √4 = -2
</span> Solution does not check
2 ≠ -2
One solution was found : <span> x = 6</span>
Answer:
The answer is (x + 3) (x - 7) = 0
Step-by-step explanation:
x² - 4x = 21
x² - 4x - 21 = 0
x² - 7x + 3x - 21 = 0
x(x - 7) + 3(x - 7) = 0
(x + 3) (x - 7) = 0
Thus, The answer is (x + 3) (x - 7) = 0
<em><u>-TheUnknownScientist</u></em>
If both C and D equal 15 then the answer is 105.
Distributive property, the parenthesis means you multiply.
