Answer:
21 in
Step-by-step explanation:
by the Pythagorean theorem we have
notice that the 841 and the 400 don't go squared because they already squared!
Using a suitable identity solve the following (7a-9b)(7a-9b)
1 answer:
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<h3>Answer:</h3>
- ABDC = 6 in²
- AABD = 8 in²
- AABC = 14 in²
A diagram can be helpful.
When triangles have the same altitude, their areas are proportional to their base lengths.
The altitude from D to line BC is the same for triangles BDC and EDC. The base lengths of these triangles have the ratio ...
... BC : EC = (1+5) : 5 = 6 : 5
so ABDC will be 6/5 times AEDC.
... ABDC = (6/5)×(5 in²)
... ABDC = 6 in²
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The altitude from B to line AC is the same for triangles BDC and BDA, so their areas are proportional to their base lengths. That is ...
... AABD : ABDC = AD : DC = 4 : 3
so AABD will be 4/3 times ABDC.
... AABD = (4/3)×(6 in²)
... AABD = 8 in²
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Of course, AABC is the sum of the areas of the triangles that make it up:
... AABC = AABD + ABDC = 8 in² + 6 in²
... AABC = 14 in²
Answer:
See attached
Step-by-step explanation:
When there is a lot of repetitive calculation to do, I like to let a spreadsheet or graphing calculator do it. The attached shows a spreadsheet that computes all the values you're asked to find.
For a linear equation in standard form, ax +by = c
- the x-intercept is: c/a
- the y-intercept is: c/b
- the slope is: m = -a/b
Of course, the slope-intercept form of the equation is ...
y = (slope)·x + (y-intercept)
and the values of the various points on the graph can be computed from that equation.
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You will note that the last two equations describe the same line.
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<em>Note on spreadsheet formulas</em>
When you put the formulas into the spreadsheet, make sure to fix the column number or row number of the values you're computing, as appropriate. For example, the y-values in the different columns always use the slope from the slope column (fixed), the y-intercept from that column (fixed), and the x-value from the top row (fixed). If you make the cell references relative instead of fixed, you will get wrong answers.
