Answer:
Gọi AH là đường cao kẻ từ A đến BC
Xét tam giác AHC vuông tại H
Suy ra AH = HC. cotA= 9.cot35° = 12,9
Xét tam giác AHB vuông tại H
Suy ra BH = AH.tanA = 12,9.tan61°=23,37
Ta có BC= HC+ HB= 9+23,27 =32,27
Diện tích tam giác ABC = 1/2 × AH ×BC= 1/2 ×12,9×32,27=208,1415
Answer:
A) 68
Step-by-step explanation:
Use the <em>Exterior Angle Theorem</em>.
The Exterior Angle theorem states that the exterior angle's measurement will be equal that of the two opposite interior angles.
Set the equation. Note that you are given the exterior angle and one interior angle:
58 + x = 126
Isolate the variable, x. Note the equal sign, what you do to one side, you do to the other. Subtract 58 from both sides of the equation:
x + 58 (-58) = 126 (-58)
x = 126 - 58
x = 68
A) 68 is your answer.
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-3n < 81...divide both sides by -3, change the inequality sign
n > -81/3
n > - 27 <==
** in an inequality, when dividing/multiplying by a negative number, the inequality sign changes
Answer:
(-9) + (-2) = -11
Step-by-step explanation:
The first arrow on the number line starts from 0, moves downwards 9 units from 0.
We would write this as -9.
Also, the next arrow starts moves from -9, 2 units downwards.
We would write this as -2
The addition equation would be:
(-9) + (-2) = -11
(x² - 3x + 7) + (3x² + 5x - 9)
(x² + 3x²) + (-3x + 5x) + (7 - 9)
4x² + 2x - 2
