Answer:
(-2, 3)
Step-by-step explanation:
4x + 5y = 7
3x - 2y = -12
Let's solve this by elimination. We want to eliminate one variable at a time. This means we need to multiply the equations to create a common multiple to cancel out a variable.
Let's work with y.
5y and -2y: For these values to cancel out, we need to multiply each term to create a common multiple.
2(4x + 5y = 7)
5(3x - 2y = -12)
Multiply.
8x + 10y = 14
15x - 10y = -60
Eliminate.
23x = -46
Divide both sides by 23.
x = -2
Now that we know x, let's plug it back into one of equations to find y.
4x + 5y = 7
4(-2) + 5y = 7
Multiply.
-8 + 5y = 7
Add.
5y = 15
Divide.
y = 3
Now we know x and y; let's plug both back into the equation we have not checked yet.
3x - 2y = -12
3(-2) - 2(3) = -12
Multiply.
-6 - 6 = -12
Subtract.
-12 = -12
Your solution is correct.
(-2, 3)
Hope this helps!
Answer:
8^5^7
Step-by-step explanation:
Multiply the numbers:
<u>4</u>X^2 y^3 x <u>2</u>x^3 y^4
<u>8</u>^2 ^3 ^3 ^4
Combine Exponents:
8<u>^2</u> ^3 <u>^3</u> ^4
8<u>^5</u> ^3 ^4
8^5 <u>^3</u> <u>^4</u>
8^5 <u>^7</u>
a = amount (in oz) of solution A
b = amount of solution B
The scientist wants a mixture of 110 oz, so
a + b = 110
Solution A consists of 65% salt, so each ounce of solution A contributes 0.65 oz of salt; similarly, each ounce of B contributes 0.9 oz. The mixture is supposed to consist of 75% salt, which amounts to 0.75 * (110 oz) = 82.5 oz of salt. So
0.65 a + 0.9 b = 82.5
Solve for a and b:
b = 110 - a
0.65 a + 0.9 (110 - a) = 82.5
0.65 a + 99 - 0.9 a = 82.5
0.25 a = 16.5
a = 66 ==> b = 44
Answer: n=75
Step-by-step explanation:
1/5 times 75 equals to 15
