18-(-4)-8 is the same as 18+4-8, or 14. You can't write the -8 as addition, but you can write the first part.
Hopefully this helps! Let me know if you have any more questions.
Answer:
m = 5/2
OR
m = 2 1/2
OR
m = 2.5
Step-by-step explanation:
Answer:
4/5
Step-by-step explanation:
i calculated it
The third choice, 4x²+18x+0.25=0, is correct.
The frame will have the same thickness on both sides of the mirror. Therefore we add 5+x+x to get the total length, and we have 4+x+x to get the total width.
The area is found by multiplying the total width and total length:
A=(5+x+x)(4+x+x)
A=(5+2x)(4+2x)
Multiplying the binomials, we have:
A=5*4+5*2x+2x*4+2x*2x
A=20+10x+8x+4x²
A=20+18x+4x²
We know that the area is 19.75:
19.75=20+18x+4x²
We need quadratics set equal to 0, so subtract 19.75 from each side:
19.75-19.75 = 20+18x+4x²-19.75
0=0.25+18x+4x²
In standard form, it will be:
4x²+18x+0.25=0
