A framed picture is shown above. The frame, shown shaded, is 6 inches wide and forms a border of uniform width around the picture. What are the dimensions of the viewable portion of the picture?
(1) The area of the shaded region is 24 square inches.
(2) The frame is 8 inches tall.
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
题目分析:
设中间部分的宽为x,长为y,因此,阴影部分的宽d=(6-x)/2,因此,本题中要求得中间部分的的面积,必然要求得x和y的值,或者x*y的值,需要两个方程才能满足要求。
(1)对于条件1,阴影部分的面积为24,即6*(y+2d)-x*y=24。
(2)对于条件2,y+2d=y+6-x=8。
综合条件1和条件2,将y+2d代入条件1,即6*8-x*y=24,x*y=24,即中间空白区域的面积为24。
综上所述,答案为(C),两个条件结合才能解题。
If you talk about the dimensions of an object or place, you are referring to its size and proportions. ----Collins Dictionary
dimension=面积?!
没懂the viewable portion of the picture -----> 求 大S - 阴影S
没懂the viewable portion of the picture -----> 求 大S - 阴影S
如果想求 阴影需要有 大正方形的 wh 以及边框宽度 x
条件1 →给了阴影部分面积 还有2个未知数 (高和边框宽度) 不充分
条件2 → 给了高度 还要一个未知 相框的宽度
结合 12 通过阴影面积和和高度 凑足 大正方形的 wh 以及相框 x
记者dimensions这个问法
画框是uniform width这个是个关键!!!设了第三个varaible
没有看清题,就是问画的面积,就总面积-阴影部分的面积就好了
解二元二次方程:
x*y = 24
6-x = 8-y
dimension n. 尺寸
老师,解法过于繁琐
1)明显不行
2)明显不行
1)+2)viewable面积=6*8-24,不就完了么,设啥未知数啊?
the viewable portion