<span>x² - 18x - 4 = ox² - 18x = 4x² - 18x + (18/2)² = 4 + (18/2)²x² - 18x + 81
</span>
The correct answer is X=6
Answer:
40
Step-by-step explanation:
Use Pythagorean Theorem to find the 3rd side, which will be 17. Then add all of the sides and you'll get the answer.
Answer:
1200 ounces
Step-by-step explanation:
How much of an alloy that is 10% copper should be mixed with 600 ounce of an alloy that is 70%copper in order to get an alloy that is 30%copper?
Let us represent
Number of ounce of 10% copper = x
Hence, our Equation =
x × 10% + 600 × 70% = (x + 600) × 30%
0.1x + 420 = (x + 600)0.3
0.1x + 420 = 0.3x + 180
Collect like terms
0.3x - 0.1x = 420 - 180
0.2x = 240
x = 240/0.2
x = 1200 ounces
Answer:
2x⁴+x³-x²+54x+56
Step-by-step explanation:
Given the expression length of dylan room = (x² – 2x + 8) and width = (2x² + 5x – 7), assuming the shap of the room is rectangular in nature, the formula for calculating area of a triangle is given as;
Area of rectangle = Length *Width
Area of the rectangle = (x² – 2x + 8)(2x² + 5x – 7)
Area of the rectangle = x²(2x² + 5x – 7) - 2x (2x² + 5x – 7) + 8(2x² + 5x – 7)
= (2x⁴+5x³-7x²)-(4x³+10x²-14x)+(16x²+40x-56)
expanding the bracket
= 2x⁴+5x³-7x²-4x³-10x²+14x+16x²+40x-56
Collecting the like terms;
= 2x⁴+5x³-4x³-7x²-10x²+16x²+40x+14x+56
= 2x⁴+x³-x²+54x+56
Hence, the expression that represents the area (lw) of Dylan's room is 2x⁴+x³-x²+54x+56
