Answer:
Step-by-step explanation:
x²+10x+21=0
x²+10x+(10/2)²-(10/2)²+21=0
x²+10x+25-25+21=0
(x+5)²-4=0
(x+5)²=4
(x+y)²=(x+y)(x+y)=x(x+y)+y(x+y)=x²+xy+xy+y²=x²+2xy+y²
(x+y)²=x²+2xy+y²
coefficient of x=2y
y²=[(coefficient of x)/2]²=(2y/2)²=y²
Answer:
a. y = -1/2x - 2
Step-by-step explanation:
The correct answer choice can be determined by finding the slope of the line. The slope is the ratio of rise to run.
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<h3>slope</h3>
The x-intercept is 4 units left of the y-axis. As the line "runs" those 4 units, it "rises" -2 units to intercept the y-axis at -2. The slope of the line is ...
m = rise/run = -2/4 = -1/2
In the slope-intercept form of the equation of a line, the slope is the coefficient of x. This information is sufficient to let us choose the first answer choice.
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<h3>equation</h3>
The slope-intercept equation is ...
y = mx +b . . . . . . . slope m, y-intercept b
We know the slope is -1/2, and the y-intercept is where x=0, at y=-2. Then the equation is ...
y = -1/2x -2 . . . . . matches choice A
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<em>Additional comment</em>
When answering multiple-choice questions, you only need to do enough work to tell which answers are <em>not</em> viable.
When we plot the points, we see that the line has negative slope. (eliminates choice C). The slope is shallow, rather than steep (the x-intercept is farther from the origin than the y-intercept), so the magnitude of the slope is less than 1 and choices B and D are eliminated.
-3^2= -(3)^2
The exponent of 2 only applies to the number 3. -(3)^2 should equal -9. This is true because according to the order of operations, exponents should be evaluated before multiplication. The negative sign here represents -1* 3^2.
If you want to find -3 to the power of 2 it must be written (-3)^2.
Answer:
D. $680
Step By Step Explanation:
100 pages are typed. Each page coast $5 to type.
100 x 5 = 500
40 pages are revised once. It costs $3 to revise a page once.
40 x 3 = 120
10 pages are revised twice. It costs $3 to revise a page once so it will cost $6 to revise it twice
10 x 6 = 60
To find the total cost we add all the amounts together
500 + 120 + 60 = 680
The final answer is $680
1/x+1/a=1/a
minus 1/a from both sides
1/x=0
false
let's try a differnt way
1/x+1/a=1/a
times both sides by xa
a+x=x
minus x from both sides
a=0
???
1/0 is undefined
this creates problems
no solution