Evaluate 3 |a| +5| b| if a=−2; b=−1 |2x−3y| if x=0.5; y=−0.7 4 |a| +8−a if a=−2 −3|x|+2x−1 if x=−5

Evaluate \dfrac13a-1-\dfrac12b 31​ a−1− 21​ bstart fraction, 1, divided by, 3, end fraction, a, minus, 1, minus, start fraction, 1, divided by, 2, end fraction, b when a=12a=12a, equals, 12 and b=6b=6b, equals, 6.\phantom{=}\dfrac13\blueD a-1-\dfrac12\goldD b= 31​ a−1− 21​ bempty space, start fraction, 1, divided by, 3, end fraction, start color blueD, a, end color blueD, minus, 1, minus, start fraction, 1, divided by, 2, end fraction, start color goldD, b, end color goldD= \dfrac13 \cdot \blueD {12}-1-\dfrac12 \cdot \goldD 6\text{Replace }\blueD{a} \text{ with } \blueD{12}\text{ and } \goldD b \text{ with } \goldD 6\text{.}= 31​ ⋅12−1− 21​ ⋅6        Replace a with 12 and b with 6.equals, start fraction, 1, divided by, 3, end fraction, dot, start color blueD, 12, end color blueD, minus, 1, minus, start fraction, 1, divided by, 2, end fraction, dot, start color goldD, 6, end color goldD, space, space, space, space, space, space, space, space, R, e, p, l, a, c, e, space, start color blueD, a, end color blueD, space, w, i, t, h, space, start color blueD, 12, end color blueD, space, a, n, d, space, start color goldD, b, end color goldD, space, w, i, t, h, space, start color goldD, 6, end color goldD, point=4 - 1 - 3=4−1−3equals, 4, minus, 1, minus, 3=0   0=0

Hello! i hope this
since the cosine is the ratio of the adjacent side to the hypotenuse, you can see that cos 60° = ½. answer. according to the property of cofunctions (topic 3), sin 30° is equal to cos 60°. sin 30° = ½.