Solve the following systems of equations using the substitution method. What is the value of a? 3a-5b=10 a+7b=12 A) a=5 B) a=6 C) a=1 D) a=7

i hope its clear . the answer is a = 5

Answer: d. 39 cmin the diagram, the approximate length of the minor arc de is 39 centimetres.step-by-step explanation: the formula for the length of an arc in a circle is as displayed below.let the length of the minor arc de = xx = 2( pi )r × angle of sector / 360°from this, we will substitute the values given from the problem into the formula to obtain the length of the minor arc de.x = 2( pi )r × angle of sector / 360°r = radius = 25cmpi as an approximate value = 3.14angle of sector = 120°x = 2( 3.14 )( 25 ) × 120° / 360°x = 157 × 1 / 4x = 39.25x = 39 ( rounded to the nearest whole number as an approximate value )

Ibelieve the answer is b. y=0 would make the line horizontal across the x.