∠BDC=30, so ∠CBD + ∠BCD=180-30=150
ΔDBC is isosceles, so ∠CBD=∠BCD=half of 150=75
∠ABC=∠ABD-∠CBD=155-75=80
ΔABC is isosceles, so ∠ABC=∠ACB=80
∠BAC=180-80-80=20
-1 < c + 2 < 3....subtract 2 from all sections
-1 - 2 < c + 2 - 2 < 3 - 2...simplify
-3 < c < 1
==============================
32 > 16 - 4g > 12....subtract 16 from all sections
32 - 16 > 16 - 16 - 4g > 12 - 16....simplify
16 > -4g > -4 ...now divide all sections by -4, and change inequality signs
16/-4 < (-4/-4)g < -4/-4...simplify
-4 < g < 1
============================
6y + 1 > = 10
6y > = 10 - 1
6y > = 9
y > = 9/6 which reduces to 3/2 or 1 1/2
-3/2y > = 9 ....multiply both sides by -2/3, cancelling the -3/2 on the left...and change the inequality sign
y < = 9 * -2/3
y < = -18/3 which reduces to - 6
so y > = 9/6(or 1 1/2) or y < = -6
The percentage of students who spend less than 4 hours a week on screens which reported a grade average below 80 is 50%
Given, we have the report representing children spending time online, on social media or watching T.V, which has there effect on there grades as above or below 80.
By the question we know that the number of students who spends less than 4 hours a week on screen is:
9 + 9
= 18
And among the 18 students there are 9 students whose grade average is below 80.
So the percentage of the students who spends 4 hours a week on screen is:
= 9 ÷ 18 × 100%
= 100/2
= 50%
hence 50% students spend less than 4 hours a week on screens.
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Answer:
1st pair of complementary angles: ∠c + ∠d
2nd pair of complementary angles: ∠g + ∠h
Step-by-step explanation:
the two solid lines are perpendicular, creating 4 right angles
1st pair of complementary angles: ∠c + ∠d
2nd pair of complementary angles: ∠g + ∠h