2x^2-7=4
subtract 4 from both sdies
2x^2-11=0
therefor
2x^2=11
divide by 2
x^2=5.5
square root both sdies
x=-2.345 or 2.345


solve for "a", once you get "a", plug it back into either equation to get "b"
By using definition of proportionality and Pythagorean theorem, the values of x and y associated with the geometrical system formed by two right triangles are 36 / 5 and 104 / 5, respectively.
<h3>How to analyze a geometrical system formed by two proportional right triangles</h3>
Herein we find a picture of a geometrical system formed by two proportional right triangles with two variables: {x, y} These variables can be found by using the definition of proportionality and the Pythagorean theorem:
5 / 8 = 12 / (12 + x) = 13 / y
Then, we proceed to solve the system formed by two equations:
(12 + x) / 12 = 8 / 5
12 + x = 96 / 5
x = 96 / 5 - 12
x = 36 / 5
y / 13 = 8 / 5
y = 104 / 5
By using definition of proportionality and Pythagorean theorem, the values of x and y associated with the geometrical system formed by two right triangles are 36 / 5 and 104 / 5, respectively.
To learn more on right triangles: brainly.com/question/6322314
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Answer:
189
Step-by-step explanation:
You can replace the values of x with 9 and the values of y with (-3).
7(2x-3y) = 7(2 × 9 - 3 × -3)
= 7(18 - -9)
= 7(18+9)
= 7 × 27
= 189