X² + y² = 225
x - 7y = -75
x = 7y - 75
x² + y² = 225
(7y-75)² + y² = 225
(7y - 75)(7y - 75) + y² = 225
49y² - 525y - 525y + 5625 + y² = 225
50y² - 1050y + 5400 = 0
50(y² - 21y + 108) = 0
y² - 21y + 108 ⇒ (y - 12)(y - 9)
x = 7(12) - 75
x = 84 - 75
x = 9 ⇒ (9,12)
x = 7(9) - 75
x = 63 - 75
x = -12 ⇒ (-12,9)
Answer:
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Step-by-step explanation:
17/5 is 8.5 but √70 is 8.3 something that for 17/2>√70
Decimal: It’s easier to work with the numbers You can add, subtract, multiply and divide in your head (for the most part) instead of having to find common denominators and things like that.
Fraction: You can put repeating values in fraction form to represent them in a simpler way, as opposed to having to put the line over the repeating digits if it were in decimal form.
Power: Powers are just condensed forms of repeated multiplication, so they save space/time and you can use certain properties with some powers that allow you to multiply and divide them instantly.
Scientific notation: This is good when you’re dealing with numbers that have a lot of digits/place value. That can become confusing, so scientific notation is a way we can represent these numbers clearly and more condensed (takes less space/time).
35% of 120 is 42. (42/32 then multiply that by 100)
92% of 125 is 115. (115/92 then multiply that by 100)