Answer: The student could use large intervals (what he counts by)
Step-by-step explanation:
The right answer is Option A.
Step-by-step explanation:
Let,
x be the postcards
y be the large envelops
According to given statement;
14x+5y=12 Eqn 1
10x+15y=24.80 Eqn 2
Multiplying Eqn 1 by 3;
Subtracting Eqn 2 from Eqn 3;
Dividing both sides by 32
Putting x=0.35 in Eqn 1;
Dividing both sides by 5
Therefore, one large envelope costs $1.42
The right answer is Option A.
Keywords: linear equations, subtraction
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Answer:
-1
Step-by-step explanation:
here is the answer
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If you have a right triangle and one angle in the triangle is 45 degrees, the other would have to be complementary (an angle that adds up to another to form a right angle) so the other angle would have to be 45 degrees to make that a right angle 90 degrees. So complementary angles are two angles that add up to equal 90 degrees.
Solve for x:
2 (6 - x) = x (x + 5)
Expand out terms of the left hand side:
12 - 2 x = x (x + 5)
Expand out terms of the right hand side:
12 - 2 x = x^2 + 5 x
Subtract x^2 + 5 x from both sides:
-x^2 - 7 x + 12 = 0
Multiply both sides by -1:
x^2 + 7 x - 12 = 0
x = (-7 ± sqrt(7^2 - 4 (-12)))/2 = (-7 ± sqrt(49 + 48))/2 = (-7 ± sqrt(97))/2:
Answer: x = (-7 + sqrt(97))/2 or x = (-7 - sqrt(97))/2
